The Effect of Low-Fat and Low-Carbohydrate Diets on Weight Loss and Lipid Levels: A Systematic Review and Meta-Analysis

Prophylactic effects of nutrition, dietary strategies, exercise, lifestyle and environment on nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and its prevalence has risen sharply. However, whether nutrition, dietary strategies, exercise, lifestyle and environment have preventive value for NAFLD remains unclear.

METHODS

Through searching 4 databases (PubMed, Web of Science, Embase and the Cochrane Library) from inception to January 2025, we selected studies about nutrition, dietary strategies, exercise, lifestyle and environment in the prevention of NAFLD and conducted a narrative review on this topic.

RESULTS

Reasonable nutrient intake encompassing macronutrients and micronutrients have an independent protective relationship with NAFLD. Besides, proper dietary strategies including mediterranean diet, intermittent fasting diet, ketogenic diet, and dietary approaches to stop hypertension diet have their inhibitory effects on the developmental process of NAFLD. Moreover, right exercises including walking, jogging, bicycling, and swimming are recommended for the prevention of NAFLD because they could effectively reduce weight, which is an important risk factor for NAFLD, and improve liver function. In addition, embracing a healthy lifestyle including reducing sedentary behavior, not smoking, sleeping well and brushing teeth regularly is integral since it not only could reduce the risk of NAFLD but also significantly contribute to overall prevention and control. Finally, the environment, including the social and natural environments, plays a potential role in NAFLD prevention.

CONCLUSION

Nutrition, dietary strategies, exercise, lifestyle and environment play an important role in the prevention of NAFLD. Moreover, this review offers comprehensive prevention recommendations for people at high risk of NAFLD.

Correlation of the Mediterranean-Dietary Approaches to Stop Hypertension diet vs. ultra-processed diet with health outcomes in type 2 diabetes and hypertension: new insights from a 12-month interventional study

BACKGROUND AND AIMS

There is ongoing debate about the optimal macronutrient and micronutrient proportions for treating type 2 diabetes (T2D) and hypertension. The objective of this study was to evaluate the dietary composition of patients participating in a 12-month interventional study with follow-up. Additionally, it aimed to evaluate the interactions and correlations between diet components and anthropometric markers, laboratory markers, and blood pressure (BP). Finally, perform a qualitative analysis of daily and postmeal satiety.

METHODS

This experimental, analytical, and correlational study is a quaternary evaluation within a recently published longitudinal research. Eighty-four participants were divided into two groups: intervention: followed a Mediterranean-DASH diet for 12 months with follow-up at 15 months; control: no dietary changes. Parametric variables were compared using two-way ANOVA and Tukey post hoc test. Nonparametric variables were compared using Kruskal-Wallis with Dwass-Steel-Critchlow-Fligner post hoc test and Friedman with Durbin-Conover post hoc test. Parametric data were represented as mean ± standard deviation, nonparametric as median ± interquartile range. Linear regression was used for interaction/relation analysis, and Pearson test for correlation. Significance was P less than 0.05.

RESULTS

Initially, both groups consumed diets high in ultra-processed foods, rich in refined carbohydrates, saturated fats, and sodium. At the 12th visit and follow-up, the intervention group showed substantial improvement in diet quality and dietary requirements (P < 0.05). The control group maintained or worsened their diet quality (P < 0.05). At first, both groups reported high hunger and low satiety. By the 12th month, the intervention group showed significant improvements, with 88.6% reporting postmeal fullness and 75% experiencing daily satiety. Significant positive and negative correlations (P < 0.05) were observed in both groups. In the control group, low-density lipoprotein cholesterol (LDL-C) was correlated with trans fats and proteins; high-density lipoprotein cholesterol (HDL-C) with polyunsaturated fats; total cholesterol (TC) with proteins and monounsaturated fats; and glycated hemoglobin (HbA1c) with fibers. In the intervention group, BMI was correlated with carbohydrates; HbA1c with total fats; LDL-C with carbohydrates; glucose with proteins; TC with total fats and carbohydrates; HDL-C with total fats, polyunsaturated fats, and saturated fats; glucose with monounsaturated fats (P < 0.05). In the intervention group, BP, heart rate, plasma, and urinary sodium levels significantly improved over time (P < 0.05). However, no strong correlations between sodium intake and these markers were observed (P > 0.05). In contrast, the control group showed no significant changes in BP, heart rate, plasma, or urinary sodium levels over time (P > 0.05), nor were there any strong correlations between sodium intake and these markers (P > 0.05). Notably, SBP, plasma, and urinary sodium levels demonstrated a significant difference between groups from the 12th month to the follow-up (P < 0.05). Additionally, DBP differed significantly from baseline, with the intervention group initially presenting higher values, which reversed by the 12th month and persisted until follow-up (P < 0.05).

CONCLUSION

The Mediterranean-DASH diet improved anthropometric, laboratory parameters, and BP in T2D and hypertension over the 12-month intervention and follow-up, whereas the ultra-processed diet worsened some of these markers. The intervention also improved satiety levels throughout the day. The quality and quantity of the diet are proportionally correlated to the anthropometric and laboratory markers. No significant strong correlations were found between plasma and urinary sodium levels, BP, or heart rate with sodium intake; only trends were observed. Nonetheless, further clinical trials are needed to establish causality, and the findings should be interpreted with caution due to the study's limitations.

Hypocaloric low-carbohydrate versus low-fat diets on flow-mediated dilation, blood pressure, cardiovascular biomarkers, and body composition in individuals with overweight or obesity: a systematic review and meta-analysis of randomized clinical trials

Obesity can impair cardiometabolism, but low-carbohydrate diets (LCDs) may be beneficial for mitigating risk. We aimed to investigate the effects of LCDs versus low-fat diets (LFDs), under hypocaloric conditions, on flow-mediated dilation (FMD) in individuals with overweight/obesity. Secondarily, we assessed other cardiovascular markers (systolic blood pressure, diastolic blood pressure, C-reactive protein [CRP], high-density lipoprotein [HDL], low-density lipoprotein [LDL], triglycerides [TG], total cholesterol [TC]), and anthropometric and body composition measurements. PubMed, Scopus, and Web of Science were searched through May 2023 for studies involving hypocaloric LCDs versus LFDs on FMD. Meta-analyses were conducted for LCDs vs. LFDs to calculate weighted mean differences (WMD), including 10 studies reporting FMD (n = 475). Overall, hypocaloric LCDs resulted in a non-significant decrease in FMD compared with hypocaloric LFDs [WMD = -1.04% (95% CI -2.28 to 0.20), p = 0.10], while very-low-carbohydrate diets (VLCDs) significantly reduced FMD when compared with LFDs [WMD = -2.12% (95% CI: -3.35 to -0.9) p = 0.001]. LCDs did not change anthropometric and body composition measurements, nor CRP, blood pressure, HDL, or TC when compared with LFDs. However, LCDs significantly decreased TG [WMD = -19.94 mg/dL (95% CI -31.83 to -8.06), p = 0.001] and increased LDL [WMD = 20.00 mg/dL (95% CI 14.09 to 25.90), p = 0.001] when compared with LFDs. In conclusion, LCDs did not exert superior effects on cardiovascular markers or body composition when compared with LFDs in individuals with overweight or obesity, but LCDs reduced TG and increased LDL levels more than LFDs. Yet, vascular function (FMD) was reduced primarily for VLCDs.

Wash-in and washout effects: mitigating bias in short term dietary and other trials

Short term trials with surrogate measures instead of hard outcomes are often used to study chronic diseases. The effects of an intervention may, however, take time to develop and persist after discontinuation, producing wash-in and washout effects that threaten trial validity. This problem, especially involving carryover effects in crossover trials, is well recognized in the pharmacology and statistics literature but commonly disregarded in some areas of non-pharmaceutical research. Dietary trials, including feeding studies, are highly susceptible to bias because physiological adaptation to a major change in nutrients may take several weeks or longer. This article describes the nature and extent of this bias in nutrition research, as an important and illustrative case; considers implications for various other interventions; and proposes measures to strengthen causal inference.

Regulation of osteoclast-mediated bone resorption by lipids

Hyperactivation of osteoclasts has been identified as a significant etiological factor in several bone resorption-related disorders, including osteoporosis, periodontitis, arthritis, and bone metastasis of tumors. It has been demonstrated that the severity of these diseases is influenced by lipids that regulate osteoclast differentiation and activity through specific signaling pathways and cytokine levels. The regulatory mechanisms of different types of lipids on osteoclastogenesis vary across diverse disease contexts in bone resorption regulated by osteoclasts. This review presents an overview of the mechanisms underlying osteoclast formation and summarizes the pathways through which various lipids regulate osteoclastogenesis in different pathological contexts. We also discuss effective therapeutic strategies for osteolytic diseases based on modulation of lipid metabolism.

Weight Reduction with GLP-1 Agonists and Paths for Discontinuation While Maintaining Weight Loss

Worldwide, nearly 40% of adults are overweight and 13% are obese. Health consequences of excess weight include cardiovascular diseases, type 2 diabetes, dyslipidemia, and increased mortality. Treating obesity is challenging and calorie restriction often leads to rebound weight gain. Treatments such as bariatric surgery create hesitancy among patients due to their invasiveness. GLP-1 medications have revolutionized weight loss and can reduce body weight in obese patients by between 15% and 25% on average after about 1 year. Their mode of action is to mimic the endogenous GLP-1, an intestinal hormone that regulates glucose metabolism and satiety. However, GLP-1 drugs carry known risks and, since their use for weight loss is recent, may carry unforeseen risks as well. They carry a boxed warning for people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. Gastrointestinal adverse events (nausea, vomiting, diarrhea) are fairly common while pancreatitis and intestinal obstruction are rarer. There may be a loss of lean body mass as well as premature facial aging. A significant disadvantage of using these medications is the high rate of weight regain when they are discontinued. Achieving success with pharmacologic treatment and then weaning to avoid future negative effects would be ideal.

A Fresh Look at Problem Areas in Research Methodology in Nutrition

This paper makes a critical evaluation of several of the research methods used to investigate the relationship between diet, health, and disease. The two widely used methods are randomized controlled trials (RCTs) and prospective cohort studies. RCTs are widely viewed as being more reliable than cohort studies and for that reason are placed higher in the research hierarchy. However, RCTs have inherent flaws and, consequently, they may generate findings that are less reliable than those from cohort studies. The text presents a discussion of the errors that may occur as a result of confounding. This refers to the correlation of the exposure and the outcome with other variables and can mask the true association or produce false associations. Another source of error is reverse causation, which is most commonly associated with cross-sectional studies. These studies do not allow researchers to determine the temporal sequence of lifestyle and other inputs together with health-related outcomes. As a result, it may be unclear which is cause and which is effect. This may also occur with cohort studies and can be illustrated by the inverse association between alcohol intake and coronary heart disease. Mechanistic research refers to the investigation of the intricate details of body functioning in health and disease and this research strategy is widely used in biomedical science. The evidence presented here makes the case that most of our information of practical value in the field of nutrition and disease has come from epidemiological research, including RCTs, whereas mechanistic research has been of minor value.

Evaluating the differential benefits of varying carbohydrate-restricted diets on lipid profiles and cardiovascular risks in dyslipidemia: a meta-analysis and systematic review

Background: carbohydrate-restricted diets (CRDs) have gained attention to address metabolic dysregulation commonly observed in dyslipidemia, a condition posing significant risks to cardiovascular health. However, the effectiveness of CRDs in improving cardiovascular health remains contentious. This meta-analysis comprehensively evaluated the long-term effects of CRDs on glucolipid metabolism and weight loss in individuals with dyslipidemia. Methods: extensive searches were conducted in PubMed, Web of Science, Scopus, the Cochrane Library, and EMBASE. Randomized controlled trials examining the effects of CRDs on glucolipid metabolism and weight loss in adults with dyslipidemia over a minimum of three weeks were included. This analysis compared the differential effects between moderate-low carbohydrate diets (MLCDs) and low carbohydrate diets (LCDs), including a targeted evaluation of animal-based CRDs and dyslipidemic individuals based on the BMI status, thereby addressing gaps in current knowledge. Results: Our findings indicated that CRDs significantly enhanced lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and apolipoprotein B (ApoB), and contributed to weight management in individuals with dyslipidemia. MLCDs were more effective than LCDs in improving all lipid profiles except for TG, which was more effectively managed by LCDs. Animal-based CRDs did not significantly impact lipid profiles. Dyslipidemic individuals with overweight and obesity showed significant changes in TG and ApoB. A noteworthy negative correlation was also observed between TC, TG, and low-density lipoprotein cholesterol levels with higher dietary fiber intake, supporting the beneficial impact of fiber on cardiovascular health. Conclusions: These results for the first time highlighted the potential of adopting MLCDs, particularly those with sufficient fiber content, as a powerful strategy for reducing the risk of cardiovascular diseases in patients suffering from dyslipidemia.

A whole-food, plant-based intensive lifestyle intervention improves glycaemic control and reduces medications in individuals with type 2 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

We conducted the largest and longest clinical trial comparing a whole-food, plant-based intervention with standard medical care (SMC) in individuals with type 2 diabetes.

METHODS

We randomised (parallel-arm; computerised 1:1 randomisation ratio) 169 adults aged 18-75 years with type 2 diabetes in the Marshall Islands to an intensive whole-food, plant-based intervention with moderate exercise (PB+Ex) or SMC for 24 weeks. The PB+Ex intervention included 12 weeks of meals, exercise sessions and group classes. Primary outcomes were glycaemic control (HbA1c, glucose, insulin and HOMA-IR) and glucose-lowering medication use. Secondary outcomes included lipids, blood pressure, heart rate and C-reactive protein. Only lab analysts were blinded.

RESULTS

Compared with SMC (n=90 randomised; n=70 analysed), the PB+Ex (n=79 randomised; n=66 analysed) intervention decreased HbA1c by an additional 14 mmol/mol (1.3%) at week 12 (-22 vs -7 mmol/mol [-2.0% vs -0.7%]; p<0.0001) and 8 mmol/mol (0.7%) at week 24 (-16 vs -8 mmol/mol [-1.4% vs -0.7%]; p=0.01). Concomitantly, 63% of medicated PB+Ex participants reduced their glucose-lowering medications (vs 24%; p=0.006), and 23% of PB+Ex participants with a baseline HbA1c <75 mmol/mol (<9%) achieved remission. Additionally, the PB+Ex intervention reduced weight (-2.7 kg; p<0.0001), C-reactive protein (-11 nmol/l; p=0.005) and cardiovascular medication use compared with SMC. At intermediate timepoints, it improved glucose, insulin, HOMA-IR, cholesterol, triglycerides and heart rate, but not at week 24.

CONCLUSIONS/INTERPRETATION

A whole-food, plant-based lifestyle intervention was more effective for improving glycaemic control than SMC. It also reduced the need for diabetes and cardiovascular medications and induced diabetes remission in some participants. Therefore, it is an effective, evidence-based lifestyle option for individuals with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03862963 FUNDING: This research was funded by the Department of the Army (W81XWH-05-1-0547). CJH received support through a National Institutes of Health Predoctoral T32 Obesity Fellowship (T32 HL105349).

The impact of dietary patterns on gut microbiota for the primary and secondary prevention of cardiovascular disease: a systematic review

BACKGROUND

Previous studies found that it is promising to achieve the protective effects of dietary patterns on cardiovascular health through the modulation of gut microbiota. However, conflicting findings have been reported on how dietary patterns impact gut microbiota in individuals either established or at risk of cardiovascular disease (CVD). Our systematic review aimed to explore the effect of dietary patterns on gut microbiota composition and on risk factors for CVD in these populations.

METHODS

We systematically searched seven databases, including PubMed/MEDLINE, MEDLINE (Ovid), Embase (Ovid), CINHAL (EBSCO), Web of Science, CNKI (Chinese), and Wanfang (Chinese), covering literature from inception to October 2024. Studies were included if they focused on adults aged 18 years and older with CVD or at least two CVD risk factors, implemented dietary pattern interventions, and incorporated outcomes related to microbiome analysis. The risk of bias for included studies was assessed using the revised Cochrane risk of bias tool (RoB2) for randomized trials and the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) for non-randomized studies. Changes in the relative abundance of the gut microbiome were summarized at various taxonomic levels, including phylum, class, order, family, genus, and species. Random-effects meta-analysis was conducted to analyze the mean difference in cardiometabolic parameters pre- and post-intervention.

RESULTS

Nineteen studies were identified, including 17 RCT and two self-controlled trails. Risk of bias across the studies was mixed but mainly identified as low and unclear. The most frequently reported increased taxa were Faecalibacterium (N = 8) with plant-rich diets, Bacteroides (N = 3) with restrictive diets, and Ruminococcaceae UCG 005 and Alistipes (N = 9) with the polyphenol-rich diets. The most frequently reported decreased taxa were Parabacteroides (N = 7) with plant-rich diets, Roseburia (N = 3) with restrictive diets, and Ruminococcus gauvreauii group (N = 6) with the polyphenol-rich diets. Plant-rich diets showed a significant decrease in total cholesterol (TC) with a mean difference of -6.77 (95% CI, -12.36 to -2.58; I2 = 84.7%), while restrictive diets showed a significant decrease in triglycerides (TG) of -22.12 (95% CI, -36.05 to -8.19; I2 = 98.4%).

CONCLUSIONS

Different dietary patterns showed distinct impacts on gut microbiota composition. Plant-rich diets promoted the proliferation of butyrate-producing bacteria, suggesting promising prospects for modulating gut microbiota and butyrate production through dietary interventions to enhance cardiovascular health. Further research is warranted to investigate the long-term effects of dietary patterns on clinical endpoints, such as CVD events or mortality.

REVIEW REGISTRATION

Registration number: CRD42024507660.

Plasma Lipid Profile Among Perimenopausal Latvian Women in Relation to Dietary Habits

Background/Objectives: Hormonal changes throughout a woman's life cycle significantly affect serum lipid levels. Alterations in the serum lipid profile can increase the risk of cardiovascular diseases (CVDs). Additionally, nutrition and dietary habits are crucial for managing dyslipidemia. The current study evaluated the association between dietary habits and plasma lipid profiles among perimenopausal women in Latvia. Methods: The randomized clinical trial involved perimenopausal women (n = 61) aged 49 ± 3 years with moderately high low-density lipoprotein cholesterol (LDL-C) levels of 3.61 ± 0.30 mmol L-1. A series of questionnaires were completed, including a questionnaire on the subject's demographic, anthropometric, lifestyle, health, physical activity, and dietary factors, a 24 h food diary, a 72 h food diary, and a food-frequency questionnaire (FFQ). Blood testing was conducted for all participants, which included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), alanine aminotransferase (ALAT), and glucose level analyses. Results: The consumption of refined sugar, honey, syrup, and jam demonstrated a strong positive association with higher levels of remnant cholesterol (β = 0.462, p ≤ 0.05) and non-high-density lipoprotein cholesterol (non-HDL-C) (β = 0.395, p ≤ 0.05). Similarly, the consumption of fruit juices is associated with increased LDL-C (β = 0.303, p ≤ 0.05) and non-HDL-C (β = 0.285, p ≤ 0.05). Conversely, higher meat and poultry consumption negatively correlates with TC levels (β = -0.290, p ≤ 0.05). Conclusions: This underscores the need for further examination to understand the impact of dietary habits on lipid profile.

The effects of low-carbohydrate diet on glucose and lipid metabolism in overweight or obese patients with T2DM: a meta-analysis of randomized controlled trials

Background

The dual burden of Type 2 Diabetes Mellitus (T2DM) and obesity is a critical public health issue. Low-carbohydrate diets have emerged as a potential intervention, yet clinical evidence remains inconclusive.

Purpose

This meta-analysis assesses the impact of low-carbohydrate diets on metabolic profiles in overweight or obese T2DM patients, aiming to guide clinical practice.

Methods

A systematic review identified randomized clinical trials (RCTs) comparing low-carbohydrate diets to control diets in T2DM patients from PubMed, Embase, and the Cochrane Library databases up to April 2023.

Results

Seventeen RCTs, encompassing 1,197 participants, demonstrated that low-carbohydrate diets significantly improved HbA1c levels and fasting plasma glucose (mean difference [MD] = -0.36, 95% CI -0.44 to -0.29, p < 0.00001; MD = -10.71, 95% CI -14.39 to -7.03, p < 0.00001). They also reduced triglycerides and increased HDL cholesterol (MD = -19.91, 95% CI -28.83 to -10.99, p < 0.00001; MD = 2.49, 95% CI 1.07-3.91, p = 0.0006), without affecting LDL and total cholesterol. Weight loss, reduced BMI, lower diastolic blood pressure, and decreased waist circumference were additional benefits.

Conclusion

Low-carbohydrate diets may enhance glycemic control and lipid profiles in overweight or obese T2DM patients, warranting consideration in T2DM management. However, the variability in diet definitions and methodologies underscores the necessity for further research to standardize dietary guidelines and evaluate long-term effects.

Metabolic syndrome therapy in pediatric age - between classic and modern. From diets to pipeline drugs

The metabolic syndrome, made up of the sum of the entities that define it (obesity, hypertension, dyslipidemias and non-alcoholic hepatic steatosis) has gained an important place in the research of the last decades. This aspect is mainly due to the complexity of management in pediatric practice. The main directions in his approach therefore bring together the concern of counteracting the noise or systemic, of the multiple intercurrents at the physiopathological level, as well as the negative imprint exerted on the quality of life. Its appearance and evolution are currently controversial topics, but the influence of genetic predisposition and lifestyle (diet, physical activity, psychological balance) are certainties. Considering the escalation of the incident at the global level, it is self-evident that it is necessary to know the pathogenesis and practice countermeasures for prophylactic or therapeutic purposes. The present work aims to summarize general aspects related to the metabolic syndrome encountered in pediatric age, with an emphasis on complementary therapeutic perspectives and their effectiveness, by analyzing the latest data from the specialized literature, accessed with the help of international databases (e.g., PubMed, Web of Science, Scopus, Embase, Google Scholar).

A network meta-analysis of the comparative efficacy of different dietary approaches on glycaemic control and weight loss in patients with type 2 diabetes mellitus and overweight or obesity

Background: Despite considerable literature supporting the benefit of dietary interventions in individuals with type 2 diabetes mellitus (T2DM) and overweight/obesity, which diet works best is currently unknown. We conducted a systematic review and network meta-analysis (NMA) to evaluate the comparative effectiveness of different dietary approaches in overweight or obese adults with T2DM. Methods: We searched EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed up till July 2023 for controlled studies using different dietary approaches. Next, we updated the literature search to September 2024 but found no new relevant studies. Glycated hemoglobin A1c (HbA1c) levels and body weight were used as primary outcomes. For each outcome, a pooled effect was determined for each intervention compared with other interventions. Mean differences (MDs) and 95% confidence intervals (95% CIs) were computed. The surface under the cumulative ranking curve (SUCRA) was used for ranking the dietary approaches. Moreover, confidence was assessed using the CINeMA (confidence in network meta-analysis) framework. Results: Overall, 31 trials that compared eight diet interventions (Mediterranean, moderate-carbohydrate, low-carbohydrate, vegetarian, low-glycaemic index/load, low-fat, high-protein and control diets) and involved 3096 people were included. In terms of glycemic control, the Mediterranean diet yielded the best ranking (SUCRA: 88.15%), followed by the moderate-carbohydrate diet (SUCRA: 83.3%) and low-carbohydrate (LC) diet (SUCRA: 55.7%). In terms of anthropometric measurements, the LC diet (SUCRA: 74.6%) ranked first, followed by the moderate-carbohydrate diet (SUCRA: 68.7%) and vegetarian diet (SUCRA: 57%). These results also showed that the differences in almost all dietary patterns regarding anthropometric measurements were mostly small and often trivial. Conclusions: In summary, the Mediterranean diet was the most efficient dietary intervention for the improvement of glycaemic control, and the LC diet obtained the highest score for anthropometric measurements in individuals with T2DM and concurrent overweight/obesity.

Anti-Obesity Effects of Sulphated Polysaccharides Derived from Marine Macro Algae or Seaweeds: A Systematic Review and Meta-Analysis

Sulphated polysaccharides (SPs) are negatively charged compounds found in the cell wall of seaweeds or marine macro algae. These compounds exhibit a range of pharmacological activities, including anti-obesity effects. The aim of this systematic review as well as meta-analysis was to assess the potentials of seaweed-derived SPs to mitigate obesity through a systematic review and meta-analysis of animal model-based studies. A comprehensive summary of the included articles was conducted, focusing on the following obesity-related parameters: food intake, body weight gain, epididymal fat size, adipocyte size, liver weight, serum alanine transaminase (ALT) and aspartate transaminase (AST), insulin and tumour necrosis factor-α (TNF-α), and the lipid profile (total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c)). The systematic review demonstrated that seaweed-derived SPs exhibit ameliorative effects against obesity, as evidenced by reductions in food intake, body weight gain, epididymal fat and adipocyte size, liver weight, ALT and AST levels, serum insulin and TNF-α, LDL-c, total cholesterol, and triglycerides and an increase in HDL-c in obese rats administered with seaweed-derived SPs. However, the meta-analysis revealed statistically significant anti-obesity effects of seaweed-derived SPs for most, but not all the parameters tested. Further research in human subjects is necessary not only to ascertain the results of preclinical studies but also to provide conclusive evidence of the anti-obesity potential of SPs in humans.

Factors Associated with Metabolically Unhealthy Obesity and Its Relation to Food Insecurity in Korean Adults with Obesity

OBJECTIVES

The association between food insecurity and metabolically unhealthy obesity (MUO) in the population with obesity is unclear. We evaluated factors associated with MUO and the relationship between food insecurity and MUO in individuals with obesity.

METHODS

We analyzed data from 5191 adults with obesity (body mass index ≥ 25 kg/m2) from the 8th Korea National Health and Nutrition Examination Survey 2019-2021. MUO was defined when participants with obesity had any of the following: (1) triglycerides ≥ 150 mg/dL, (2) High-density lipoprotein-cholesterol < 40 mg/dL (men), <50 mg/dL (women), (3) systolic blood pressure ≥ 135 mmHg, diastolic blood pressure ≥85 mmHg or on treatment for hypertension, (4) fasting glucose ≥ 100 mg/dL, or on treatment for diabetes. The odds ratios (ORs) and 95% confidence intervals (CIs) for MUO according to food security status, sociodemographic characteristics, and lifestyle factors were calculated using multivariate logistic regression analysis.

RESULTS

The prevalence of MUO and metabolically healthy obesity (MHO) among the participants was 85.4% and 14.6%, respectively. In the multivariate model, the OR (95% CIs) for MUO in the food insecurity group was 1.87 (1.03-3.43). The odds for MUO were higher among participants with older age, higher BMI, <12 years of education, lower fat intake, non-manual work, and moderated and low physical activity than among their counterparts.

CONCLUSIONS

Food insecurity, older age, higher BMI, lower educational level, lower fat intake, non-manual workers, and lower physical activity were associated with MUO. Therefore, targeted interventions and policies are needed for vulnerable groups.

Asian Low-Carbohydrate Diet with Increased Whole Egg Consumption Improves Metabolic Outcomes in Metabolic Syndrome: A 52-Week Intervention Study

BACKGROUND

The low-carbohydrate-ketogenic diet, an effective strategy to address metabolic syndrome (MetS) and obesity has raised concerns about high-fat consumption on atherogenic lipoproteins.

OBJECTIVE

The aim of this study was to compare the Asian ketogenic diet (AKD), which incorporates balanced protein and fat intake from Asian foods, with a balanced low-caloric diet (BLC) in individuals diagnosed with MetS.

METHODS

A 52-wk randomized clinical trial included 3 parallel groups: AKD with increased whole egg intake [egg yolk Asian ketogenic diet (Yolk-AKD, n = 28)], yolk-free ketogenic diet with egg white supplementation [egg white Asian ketogenic diet (White-AKD, n = 26)], and BLC (n = 22). Primary outcomes were anthropometric and metabolic changes.

RESULTS

The AKD groups achieved significant reductions in weight and waist circumference (P < 0.05). Compared with the BLC group, the AKD groups demonstrated significant improvements in insulin resistance at week 6 and in triglyceride concentrations at weeks 12 (Yolk-AKD) and 35 (White-AKD) (P < 0.05). The AKD groups experienced improvements in hormones associated with insulin sensitivity and appetite, whereas only the Yolk-AKD group had a significant decrease in inflammation-related hormones (P < 0.05). From weeks 35-52, the AKD maintained reductions in anthropometric measurements, blood pressure, improved glucose tolerance, enhanced lipid profiles, and better liver function compared with the BLC.

CONCLUSIONS

The AKD proved safe and effective, yielding various metabolic improvements in individuals with MetS compared with the BLC. Emphasizing a low-saturated fat diet while disregarding dietary cholesterol, this approach holds promise for MetS and obesity management. The inclusion of both White-AKD and Yolk-AKD groups allowed for a comprehensive assessment of the AKD's impact, elucidating the differential effects of whole egg consumption on metabolic outcomes. Further studies are warranted. This trial was registered at clinicaltrials.gov as NCT04608136.

Short-term high-fat and high-carb diet effects on glucose metabolism and hedonic regulation in young healthy men

Background

Daily dietary intake of macronutrients and energy is closely associated with long-term metabolic health outcomes, but whether 24-h nutritional intervention under isocaloric conditions leads to changes in metabolism remains unclear. Moreover, the short-term effect of diets with different macronutrient composition on hedonic appetite regulation is less clear.

Methods

This study examined the impact of an acute high-fat (F+) and high-carbohydrate (C+) diet on glucose metabolism and hedonic regulation of food intake in young healthy men under controlled conditions. Using a cross-over design, 19 male participants received a one-day isocaloric diet with different macronutrient composition (F+ = 11% carbohydrates, 74% fat; C+ = 79% carbohydrates, 6% fat) compared to a control diet (CON = 55% carbohydrates, 30% fat). Protein content was set at 15% of energy in all diets. The feeling of hunger, as well as "liking" and "wanting" for foods, was assessed through visual analog scales, and blood samples for glucose, insulin, and cortisol levels were assessed repeatedly during the experimental day. An intravenous glucose tolerance test was conducted the next morning.

Results

Postprandial glucose and insulin levels were lowest in F+ over the 24 h. Except for dinner, the CON diet showed the highest mean values in glucose. F+ diet improved insulin resistance, lowering Homeostatis Model Assessment Insulin Resistance (HOMA-IR) values. Changes in hedonic regulation of food intake were not observed during the intervention between the diets, except for higher feelings of satiety under the CON diet.

Conclusion

An acute, isocaloric, high-fat diet improved insulin resistance even in healthy individuals but did not affect hedonic food intake regulation. Macronutrient composition modulate glucose metabolism even under short-term (24-h) and isocaloric diets, which should be considered for personalized preventive dietary treatments.

Effect of Yoga Therapy on Hypothyroidism: A Systematic Review

Background

Hypothyroidism (HT) is the most prevalent endocrine disorder, affecting approximately one in 10 out of 35 adults, with a higher prevalence in females and the elderly.

Purpose

This systematic review (SR) aimed to discuss the effects of yoga on markers and comorbid conditions of HT.

Methods

The SR was registered with the PROSPERO (PROSPERO 2022 CRD42022312990). Google Scholar, PubMed, Cochrane, and EMBASE were searched for the relevant English language interventional studies published from 31 December 1947 to 31 December 2023 by using the keywords 'meditation OR breath regulation OR yoga OR yoga nidra AND hypothyroidism OR hypothyreosis OR underactive thyroid OR low thyroid'. Of the 4078 screened studies, eight eligible studies (three RCTs, two pilot studies, two pre-post trials, and one case study) with 421 HT patients (392 females and 29 males) and three to six-month yoga interventions were included. Two independent review authors extracted study characteristics and synthesised them descriptively. RCTs and NRSIs were assessed for risk-of-bias (RoB) using Cochrane tools RoB2 and ROBINS-1.

Results

The findings suggest that yoga effectively improves the thyroid profile, lipid profile, heart rate variability, pulmonary functions, anxiety, depression, and quality of life among HT patients.

Conclusion

Yoga may be an inexpensive add-on preventive and therapeutic option for HT. The clinical and methodological heterogeneity among the studies did not allow for meta-analysis (MA). Well-designed MAs are warranted by including rigorous RCTs to draw valid conclusions and defined mechanisms regarding the efficacy of yoga practices/interventions on HT.

Association between carbohydrate to protein or fat ratio and mortality: A prospective cohort study

BACKGROUND & AIMS

The effect of dietary macronutrient balance on longevity and metabolic health remains a subject of considerable interest. We aimed to investigate the association of carbohydrate-to-protein and carbohydrate-to-fat ratios with all-cause and cardiovascular mortalities.

METHODS

In this population-based study, data from the Korean Genome and Epidemiology Study were integrated with those from national data sources, including mortality records from the Korea National Statistical Office. The primary outcomes were all-cause and cardiovascular mortalities. Carbohydrate-to-protein and carbohydrate-to-fat ratios were evaluated based on dietary habits assessed through a food frequency questionnaire. Harrell's C-index was employed to determine optimal cut-off points for carbohydrate-to-protein and carbohydrate-to-fat ratios. Cox proportional hazards regression models were used to assess associations.

RESULTS

A total of 143,050 participants aged ≥40 years were included in the analyses. Compared with individuals with non-elevated carbohydrate-to-protein ratios (<5.2), those with elevated carbohydrate-to-protein ratios (>9.9) exhibited a higher all-cause mortality (hazard ratio 1.09, 95% confidence interval 1.01-1.17); however, no correlation between carbohydrate-to-protein ratio and cardiovascular mortality (hazard ratio 1.13, 95% confidence interval 0.96-1.32) was observed. Compared with those with non-elevated carbohydrate-to-fat ratios (<5.1), those with higher carbohydrate-to-fat ratios (>7.1) exhibited increased all-cause (hazard ratio 1.08, 95% confidence interval 1.00-1.16) and cardiovascular (hazard ratio 1.27, 95% confidence interval 1.06-1.52) mortalities.

CONCLUSIONS

Our findings regarding macronutrient ratios and their association with mortality suggest that reducing excessive carbohydrate intake and increasing the consumption of protein and fats may have beneficial effects on longevity and cardiovascular health. Further studies are needed to understand the underlying mechanisms of these effects.

Impact of low-carbohydrate diet on health status: an umbrella review

Introduction

The prevalence of diet-related non-communicable diseases has increased. A low-carbohydrate diet (LCDs) is one of the most popular interventions. Several systematic reviews and meta-analyses of randomised clinical trials (RCTs) and non-RCTs have linked LCDs to the management of obesity, diabetes, cardiovascular disease, epilepsy, and cancer. However, there has been limited appraisal of the strength and quality of this evidence.

Objective

To systematically appraise existing meta-analyses and systematic reviews of RCTs and non-RCTs on the effects of LCDs on different health conditions. To understand their potential efficacy, we summarised the studies' findings and assessed the strength of the evidence.

Methods

A search was conducted using the PubMed database from inception to October 2021 for systematic reviews and meta-analyses of RCTs and non-RCTs investigating the association between LCDs and multiple health outcomes in humans. The Academy of Nutrition and Dietetics Quality Criteria was used for the quality assessment. In addition, the evolution of heterogeneity, strength of the included studies, and effect sizes were extracted from each systematic review and meta-analysis.

Results

Ten systematic reviews and meta-analyses were included. Of the included reviews, 70% were of positive quality, 30% were neutral, and none were negative. The majority of the studies included strength in each systematic review, and the meta-analyses were of low to medium strength. The existing literature indicates that LCDs may help promote weight reduction in adults who are obese or overweight. This conclusion is supported by the findings of studies included in the analysis, which were of low to moderate strength. Furthermore, compelling data indicates a significant association between low-carbohydrate diets (LCDs) and a reduction in haemoglobin A1c levels among those diagnosed with type 2 diabetes mellitus. In contrast, there was a lack of evidence of this correlation in type 1 diabetes mellitus patients or those with cardiovascular diseases. Additionally, there was limited evidence regarding the effectiveness of LCDs in epilepsy and adult cancer patients.

Conclusion

This review thoroughly examines the current body of information on how LCDs affect various health outcomes. Studies have presented evidence to support the idea that incorporating LCDs can positively influence weight management and HbA1c levels. However, there is a lack of information regarding the association between LCDs and individuals with Type 1 diabetes mellitus and cardiovascular diseases. Additionally, there is limited empirical evidence to substantiate the effectiveness of LCDs in the treatment of epilepsy and adult cancer patients. The long-term effects of LCDs on mortality and other chronic diseases that account for different carbohydrate subtypes is unclear. Further longitudinal cohort studies are required to reach definitive conclusions.

2024 KSoLA consensus on secondary dyslipidemia

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

2024 KSoLA Consensus on Secondary Dyslipidemia

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

Very Low Calorie Ketogenic Diet: What Effects on Lipid Metabolism?

PURPOSE OF REVIEW

This review aims to critically examine how VLCKD affects plasma lipoprotein, lipid and cholesterol metabolism. Cardiovascular disease is a worldwide health problem affecting millions of people and leading to high rates of mortality and morbidity. There is a well-established association between cardiovascular disease and circulating cholesterol. Various dietary recommendations are currently available for the management of dyslipidemia.

RECENT FINDINGS

The very low-calorie ketogenic diet (VLCKD) is becoming increasingly popular as a treatment option for several pathological conditions, including dyslipidemia. In addition to being low in calories, the VLCKD's main feature is its unique calorie distribution, emphasizing a reduction in carbohydrate consumption in favor of fat as the primary calorie source. Lowering calorie intake through a VLCKD can reduce the endogenous production of cholesterol. However, if the foods consumed are from animal sources, dietary cholesterol intake may increase due to the higher fat content of animal products. When combined, these dietary practices may have opposing effects on plasma cholesterol levels. Studies investigating the impact of VLCKD on plasma cholesterol and low-density lipoprotein cholesterol levels report contradictory findings. While some studies found an increase in low-density lipoprotein cholesterol levels, others showed a decrease in total cholesterol and low-density lipoprotein cholesterol, along with an increase in high-density lipoprotein cholesterol.

Nutritional Considerations During Major Weight Loss Therapy: Focus on Optimal Protein and a Low-Carbohydrate Dietary Pattern

PURPOSE OF REVIEW

Considering the high prevalence of obesity and related metabolic impairments in the population, the unique role nutrition has in weight loss, reversing metabolic disorders, and maintaining health cannot be overstated. Normal weight and well-being are compatible with varying dietary patterns, but for the last half century there has been a strong emphasis on low-fat, low-saturated fat, high-carbohydrate based approaches. Whereas low-fat dietary patterns can be effective for a subset of individuals, we now have a population where the vast majority of adults have excess adiposity and some degree of metabolic impairment. We are also entering a new era with greater access to bariatric surgery and approval of anti-obesity medications (glucagon-like peptide-1 analogues) that produce substantial weight loss for many people, but there are concerns about disproportionate loss of lean mass and nutritional deficiencies.

RECENT FINDINGS

No matter the approach used to achieve major weight loss, careful attention to nutritional considerations is necessary. Here, we examine the recent findings regarding the importance of adequate protein to maintain lean mass, the rationale and evidence supporting low-carbohydrate and ketogenic dietary patterns, and the potential benefits of including exercise training in the context of major weight loss. While losing and sustaining weight loss has proven challenging, we are optimistic that application of emerging nutrition science, particularly personalized well-formulated low-carbohydrate dietary patterns that contain adequate protein (1.2 to 2.0 g per kilogram reference weight) and achieve the beneficial metabolic state of euketonemia (circulating ketones 0.5 to 5 mM), is a promising path for many individuals with excess adiposity.

Nutrient analysis of three low-carbohydrate diets differing in carbohydrate content

Introduction

Low-carbohydrate diets are increasing in popularity. Despite clinical evidence demonstrating their safety and efficacy, concerns regarding the nutrient adequacy of low-carbohydrate diets persist. The aims of this study were to assess the nutrient adequacy of three 7-day meal plans that delivered 20 (VLCD20), 40 (VLCD40), and 100 (LCD100) grams of net carbohydrate per day respectively.

Methods

Nutrient analyses were conducted using USDA Food Data Central.

Results

All three low-carbohydrate meal plans exceeded recommendations for vitamins A, C, D, E, K, thiamin, riboflavin, niacin, B6, folate and B12 in males and females 31-70 years and exceeded calcium recommendations for adults 31-50 years but remained below the Tolerable Upper Intake Level. VLCD40 and LCD100 met or exceeded fiber recommendations for females ages 31-70 years and were adequate for males 51-70 years. None of the meal plans contributed meaningful amounts of added sugar. The plans exceeded the Recommended Dietary Allowance for protein for adults ages 31-70 years of age but were within the Acceptable Macronutrient Distribution Range of 10-35% of energy. The plans slightly exceeded recommendations for saturated fat and sodium but were lower in these nutrients than the average American diet and had more favorable omega-6 to omega-3 and sodium to potassium ratios than is typical. All three meals plans met or exceeded the Estimated Average Requirement for micronutrients in females ages 31-50 years, the population group most likely to consume low-carbohydrate diets.

Discussion

Well-constructed low-carbohydrate meal plans can be nutritionally adequate in adults.

Factors Associated with the Practice of Low-Carb and Low-Fat Diets among Participants of the Longitudinal Study of Adult Health (ELSA-Brasil)

In the field of nutrition, both low-carbohydrate (LCD) and low-fat (LFD) diets were initially intended for specific subgroups but are now being embraced by the broader population for various purposes, including aesthetics and overall health. This study aims to assess sociodemographic, health, and lifestyle factors influencing diet choices among public servants in the ELSA-Brasil cohort. Diets were classified as LCD or LFD based on the Brazilian Diabetes Society (<45%) and WHO guidelines (<30%) respectively. A total of 11,294 participants were evaluated (45.3% men; 54.7% women) with a mean age of 52 ± 0.08 years. Having overweight, altered waist circumference, and a history of smoking confers higher chances of adopting an LCD compared to the usual diet, while being over 52 years, non-White race/skin color, in a lower income stratum, and having diagnosis of hypertension and/or diagnosis of diabetes mellitus decrease these chances. Regarding LFDs, belonging to the non-White race/skin color, being over 52 years old, being divorced, and practicing low physical activity decrease the chances of following such a diet compared to the usual diet. In conclusion, factors like age, socioeconomic status, health, and physical activity levels can be the key to understanding why individuals choose restrictive diets beyond clinical advice.

Low-Carbohydrate Diet is More Helpful for Weight Loss Than Low-Fat Diet in Adolescents with Overweight and Obesity: A Systematic Review and Meta-Analysis

Purpose

This manuscript performed a meta-analysis to compare the effects of a low-fat diet (LFD) and a low-carbohydrate diet (LCD) on body weight and lipid levels in adolescents with overweight and obesity.

Patients and Methods

PubMed and other databases were searched for the full-text literature comparing LFD and LCD up to November 2023 using a subject plus free word strategy, with search terms such as "low-fat diet", "low-carbohydrate diet", "obesity", "weight", "adolescents", "RCT", and so on. Two independent reviewers selected promising candidate trials, collected the data, and assessed the quality of the trials. RevMan 5.3 software was utilized to conduct a meta-analysis of the randomized controlled trials (RCTs) that were included.

Results

5 RCTs with 192 participants were included in this meta-analysis. Weight (mean difference -2.81; 95% CI -5.38 to -0.25), Body Mass Index (BMI) (-1.13; 95% CI -2.14 to -0.11) and Triglyceride (TG) (-0.36; 95% CI -0.46 to -0.27) of the LCD were significantly lower than that of the LFD. At the same time, the high-density lipoprotein cholesterol (HDL) levels of the LCD were significantly higher than those of the LFD (0.08; 95% CI 0.04 to 0.12) (P < 0.05). However, there was no significant difference in the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), percent body fat, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL) between the two groups (P>0.05).

Conclusion

According to this study, LCD is more helpful in improving weight loss, HDL and TG. Thus, LCD may serve as an effective intervention for weight management in adolescents with overweight and obesity, although further research is needed to determine its long-term effects.

Diet and physical activity interventions to improve cardiovascular disease risk factors in liver transplant recipients: Systematic review and meta-analysis

BACKGROUND AND AIMS

Cardiovascular disease, associated risk factors and obesity are prevalent after liver transplant and modifiable through lifestyle changes. Understanding what lifestyle interventions and their respective components are effective is essential for translation to clinical practice. We aimed to investigate the effects of diet and physical activity interventions on weight, body mass index and other cardiovascular disease risk factors in liver transplant recipients, and systematically describe the interventions.

METHODS

We systematically searched Embase, MEDLINE, Psycho Info, CINAHL, Cochrane central register of controlled trials, PeDro, AMED, BNI, Web of Science, OpenGrey, ClinicalTrials.gov and the international clinical trials registry from inception to 31 May 2023. Search results were screened by two independent reviewers: randomised control trials with interventions that targeted diet and physical activity behaviours in liver transplant recipients were considered eligible. Two independent reviewers extracted and synthesised data for study, participant and intervention details and results. We used the Revised Cochrane Risk of Bias Tool for Randomised Trials to assess risk of bias for outcomes and the GRADE approach to rate the quality of the body of evidence. When two or more studies reported findings for an outcome, we pooled data using random-effects meta-analysis.

RESULTS

Six studies were included, reporting three physical activity and three combined diet and physical activity interventions. Participants were 2 months-4 years post-transplant. Interventions lasted 12 weeks-10 months and were delivered remotely and/or in-person, most commonly delivered to individual participants by health care or sports professionals. Five studies described individual tailoring, e.g. exercise intensity. Adherence to interventions ranged from 51% to 94%. No studies reported fidelity. Intervention components were not consistently reported. In meta-analysis, diet and physical activity interventions did not significantly reduce weight or body mass index compared to control groups, however no studies targeted participants with obesity. Diet and physical activity interventions reduced percentage body fat and triglycerides compared to control groups but did not reduce total cholesterol or increase activity. The GRADE quality of evidence was low or very low.

CONCLUSION

Diet and physical activity interventions reduced percentage body fat and triglycerides in liver transplant recipients. Further good quality research is needed to evaluate their effect on other cardiovascular disease risk factors, including weight and BMI. Interventions need to be better described and evaluated to improve evidence base and inform patient care.

Effects of a personalized nutrition program on cardiometabolic health: a randomized controlled trial

Large variability exists in people's responses to foods. However, the efficacy of personalized dietary advice for health remains understudied. We compared a personalized dietary program (PDP) versus general advice (control) on cardiometabolic health using a randomized clinical trial. The PDP used food characteristics, individual postprandial glucose and triglyceride (TG) responses to foods, microbiomes and health history, to produce personalized food scores in an 18-week app-based program. The control group received standard care dietary advice (US Department of Agriculture Guidelines for Americans, 2020-2025) using online resources, check-ins, video lessons and a leaflet. Primary outcomes were serum low-density lipoprotein cholesterol and TG concentrations at baseline and at 18 weeks. Participants (n = 347), aged 41-70 years and generally representative of the average US population, were randomized to the PDP (n = 177) or control (n = 170). Intention-to-treat analysis (n = 347) between groups showed significant reduction in TGs (mean difference = -0.13 mmol l-1; log-transformed 95% confidence interval = -0.07 to -0.01, P = 0.016). Changes in low-density lipoprotein cholesterol were not significant. There were improvements in secondary outcomes, including body weight, waist circumference, HbA1c, diet quality and microbiome (beta-diversity) (P < 0.05), particularly in highly adherent PDP participants. However, blood pressure, insulin, glucose, C-peptide, apolipoprotein A1 and B, and postprandial TGs did not differ between groups. No serious intervention-related adverse events were reported. Following a personalized diet led to some improvements in cardiometabolic health compared to standard dietary advice. ClinicalTrials.gov registration: NCT05273268 .

The role of lipid metabolism in osteoporosis: Clinical implication and cellular mechanism

In recent years, researchers have become focused on the relationship between lipids and bone metabolism balance. Moreover, many diseases related to lipid metabolism disorders, such as nonalcoholic fatty liver disease, atherosclerosis, obesity, and menopause, are associated with osteoporotic phenotypes. It has been clinically observed in humans that these lipid metabolism disorders promote changes in osteoporosis-related indicators bone mineral density and bone mass. Furthermore, similar osteoporotic phenotype changes were observed in high-fat and high-cholesterol-induced animal models. Abnormal lipid metabolism (such as increased oxidized lipids and elevated plasma cholesterol) affects bone microenvironment homeostasis via cross-organ communication, promoting differentiation of mesenchymal stem cells to adipocytes, and inhibiting commitment towards osteoblasts. Moreover, disturbances in lipid metabolism affect the bone metabolism balance by promoting the secretion of cytokines such as receptor activator of nuclear factor-kappa B ligand by osteoblasts and stimulating the differentiation of osteoclasts. Conclusively, this review addresses the possible link between lipid metabolism disorders and osteoporosis and elucidates the potential modulatory mechanisms and signaling pathways by which lipid metabolism affects bone metabolism balance. We also summarize the possible approaches and prospects of intervening lipid metabolism for osteoporosis treatment.

Effects of low-carbohydrate diets, with and without caloric restriction, on inflammatory markers in adults: a systematic review and meta-analysis of randomized clinical trials

Low-carbohydrate diets (LCDs) have gained interest due to their favorable effects on health outcomes, such as inflammation. However, further research is needed to ascertain the overall effects of LCDs on inflammatory parameters, but at the same time considering weight loss and calorie intake. Thus, a systematic review and meta-analysis of randomized clinical trials was performed to investigate the effects of LCDs compared with low-fat diets (LFDs), with and without caloric restriction, on inflammatory markers in adults. PubMed, Scopus, and Web of Science were searched through March 2022 to select intervention studies addressing LCDs vs. LFDs, in which the following circulating inflammatory markers were used: C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), and interleukin (IL-6). Analyses were conducted comparing LCDs vs. LFDs through weighted mean differences (WMD) or standardized mean differences (SMD) and 95% confidence intervals (95% CIs) using random effects models. The systematic review and meta-analysis included a total of 51 studies with a total sample of 4,164 adults, with or without other chronic diseases. Intervention durations ranged from 2-144 weeks. LCDs, compared with LFDs, significantly decreased body weight [WMD = -1.35%, p = 0.001], CRP [SMD = -0.1, p = 0.03], and IL-6 [SMD = -0.15, p = 0.09]. However, LCDs did not significantly decrease TNF-α [SMD = -0.02, p = 0.7] compared to LFDs. In conclusion, LCDs have a beneficial effect on markers of inflammation by decreasing CRP and IL-6; this effect has an association with weight loss. However, LCDs were not more effective than LFDs in decreasing TNF-α.

Role of lifestyle and glucagon-like peptide-1 receptor agonists for weight loss in obesity, type 2 diabetes and steatotic liver diseases

BACKGROUND

The current obesity pandemic has given rise to associated comorbidities and complications, including type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). During the last decade, certain glucagon-like peptide 1 receptor agonists (GLP-1RA), originally developed as antihyperglycemic drugs, also demonstrated efficacy for weight loss.

AIMS

To review shared pathophysiologic features of common metabolic diseases and compare therapeutic strategies to reduce body weight and related complications.

METHODS

We performed an extensive literature research to describe the effects of lifestyle modification, first-generation anti-obesity drugs, and GLP-1RA on weight loss in humans with obesity, type 2 diabetes and MASLD.

RESULTS

Until recently, treatment of obesity has been limited to lifestyle modification, which offer moderate degree and sustainability of weight loss. The few approved first-generation anti-obesity drugs are either limited to short term use or to certain forms of obesity. Some GLP-1RA significantly decrease caloric intake and body weight. Liraglutide and semaglutide have therefore been approved for treating people with obesity. They also lead to a reduction of hepatic fat content and inflammation in people with biopsy-confirmed MASLD. Possible limitations comprise adverse effects, treatment adherence and persistence.

CONCLUSION

Certain GLP-1RA are superior to lifestyle modification and first-generation anti-obesity drugs in inducing weight loss. They have therefore markedly changed the portfolio of obesity treatment with additional beneficial effects on steatotic liver disease.

Genetics, pharmacotherapy, and dietary interventions in childhood obesity

Childhood obesity has emerged as a major global health issue, contributing to the increased prevalence of chronic conditions and adversely affecting the quality of life and future prospects of affected individuals, thereby presenting a substantial societal challenge. This complex condition, influenced by the interplay of genetic predispositions and environmental factors, is characterized by excessive energy intake due to uncontrolled appetite regulation and a Westernized diet. Managing obesity in childhood requires specific considerations compared with adulthood, given the vulnerability of the critical juvenile-adolescent period to toxicity and developmental defects. Consequently, common treatment options for adult obesity may not directly apply to younger populations. Therefore, research on childhood obesity has focused on genetic defects in regulating energy intake, alongside pharmacotherapy and dietary interventions as management approaches, with an emphasis on safety concerns. This review aims to summarize canonical knowledge and recent findings on genetic factors contributing to childhood obesity. Additionally, it assesses the efficacy and safety of existing pharmacotherapies and dietary interventions and suggests future research directions. By providing a comprehensive understanding of the complex dynamics of childhood obesity, this review aims to offer insights into more targeted and effective strategies for addressing this condition, including personalized healthcare solutions.

Should carbohydrate-modified diets be the first option for weight loss in people with impaired glucose metabolism? A scoping review

While the "precision nutrition" movement is at an early stage of development, several investigations have compared low-fat versus carbohydrate (CHO)-modified diets (i.e., low-or-reduced-CHO, low glycemic index/load diets, and high-fiber) in people with normal versus impaired glucose metabolism. The purpose of this scoping review was to summarize evidence in support of the hypothesis that CHO-modified diets are more effective for weight loss among people with impaired glucose metabolism. Fifteen articles were included in this review: seven retrospective analyses of randomized clinical trials and eight prospective randomized clinical trials with prespecified hypotheses related to a diet (low-fat vs. CHO-modified) × phenotype (normal vs. impaired) interaction. Evidence in support of the hypothesis was identified in six of seven retrospective and three of eight prospective studies, which led to a recommendation of CHO-modified diets as a first-line option for people with impaired glucose metabolism. However, the evidence in support of this recommendation is relatively weak, and dietary prescriptions should consider additional contextual information that may influence overall dietary adherence. Additional and rigorous research using innovative randomized experimental approaches is needed for stronger dietary weight loss recommendations based on pretreatment glycemic status.

Low-carbohydrate dietary score and the incidence of metabolically unhealthy phenotype based on BMI status: a cohort study

There is scarce research focusing on the relationship between the low-carbohydrate dietary score and the development of a metabolically unhealthy phenotype. Therefore, this cohort study was designed to assess the association between the low-carbohydrate dietary score and the risk of metabolically unhealthy phenotypes (MUP). This study included 1299 adults with healthy metabolic profiles who were followed for 5.9 years. Results indicated an inverse association between the second tertile of the low-carbohydrate dietary score and the risk of developing metabolically unhealthy obesity (MUO) (HR: 0.76, 95% CI: 0.59-0.98). In addition, we found an inverse association between the healthy low-carbohydrate dietary score and the risk of MUO (HR: 0.77, 95% CI: 0.60-0.99). Our results revealed a nonlinear inverse association between the low-carbohydrate dietary score and the risk of MUP only in subjects with overweight or obesity. This relationship was independent of animal protein and fat intake. Also, we found that a lower intake of unhealthy carbohydrates was associated with a lower risk of MUP only in subjects with overweight or obesity.

Cholesterol mediates the effects of single and multiple environmental phenols in urine on obesity

BACKGROUND

Overweight and obesity are among the leading chronic diseases worldwide. Environmental phenols have been renowned as endocrine disruptors that contribute to weight changes; however, the effects of exposure to mixed phenols on obesity are not well established.

METHODS

Using data from adults in National Health and Nutrition Examination Survey, this study examined the individual and combined effects of four phenols on obesity. A combination of traditional logistic regression and two mixed models (weighted quantile sum (WQS) regression and Bayesian kernel-machine regression (BKMR)) were used together to assess the role of phenols in the development of obesity. The potential mediation of cholesterol on these effects was analyzed through a parallel mediation model.

RESULTS

The results demonstrated that solitary phenols except triclosan were inversely associated with obesity (P-value < 0.05). The WQS index was also negatively correlated with general obesity (β: 0.770, 95% CI: 0.644-0.919, P-value = 0.004) and abdominal obesity (β: 0.781, 95% CI: 0.658-0.928, P-value = 0.004). Consistently, the BKMR model demonstrated the significant joint negative effects of phenols on obesity. The parallel mediation analysis revealed that high-density lipoprotein mediated the effects of all four single phenols on obesity, whereas low-density lipoprotein only mediated the association between benzophenol-3 and obesity. Moreover, Cholesterol acts as a mediator of the association between mixed phenols and obesity. Exposure to single and mixed phenols significantly and negatively correlated with obesity. Cholesterol mediated the association of single and mixed environmental phenols with obesity.

CONCLUSIONS

Assessing the potential public health risks of mixed phenols helps to incorporate this information into practical health advice and guidance.

Macronutrients modified dietary intervention in the management of overweight/obese children and adolescents: a systematic review

The prevalence of obesity in adults and children is rapidly increasing worldwide. Obesity is among the main causes of chronic diseases and various problems, including economic consequences and they can also be affected by genetic, environmental, psychological, and socioeconomic factors. Dietary modification is a well-known and important factor in weight control, in particular, dietary macronutrient composition, food selection, dietary patterns, and energy restriction can affect weight reduction. Therefore, this systematic review aims to provide basic evidence for identifying the optimal macronutrient composition for managing obesity in Korean children and adolescents. We searched literature through an international database, studies were selected using our eligibility criteria and quality was assessed via a risk of bias tool. In our results, several studies have demonstrated that dietary macronutrient modifications affect body composition and metabolic markers in children and adolescents. In contrast, hypocaloric diets, regardless of macronutrient composition, are reportedly effective for weight loss in obese children. However, these findings were based on intervention studies that examined the association between dietary macronutrient composition and obesity in non-Korean children and adolescents. Therefore, in the future, more intervention studies are needed to elucidate this relationship and evidence between macronutrients and obesity in Korean children and adolescents.

The association of dietary carbohydrate quality and quantity with obesity among Iranian adolescents: a case-control study

BACKGROUND

Adolescent obesity is considered as a major health concern worldwide which is closely linked to the quality of diet. The purpose of the present study was to assess the carbohydrate quality and quantity in relation to odds of overweight and obesity in adolescents.

METHODS

This case-control study with a 1:1 ratio was conducted on 406 adolescents (14 to 18 years old) matched for age and gender. Participants were selected by multistage cluster random sampling method from March to October 2019 in Shiraz, Iran. Dietary intakes of the study population were assessed by a validated semi-quantitative food frequency questionnaire. Also anthropometric indices were measured using standard methods and demographic information was recorded via face to face interview. The relation between low carbohydrate diet score (LCDS) and carbohydrate quality index (CQI), and odds of obesity was evaluated by multiple Logistic regression.

RESULTS

After adjusting the role of potential confounders, the participants in the third tertiles of LCDS (OR = 0.443, 95% CI = (0.260 to 0.755)) and CQI (OR = 0.005, 95% CI = (0.001 to 0.025)) had less odds of being overweight and obese compared to the first tertile.

CONCLUSION

The present study found an inverse relationship between dietary quantity and quality of carbohydrate intake and the odds of overweight and obesity in a sample of Iranian adolescents.

Increased low-density lipoprotein cholesterol on a low-carbohydrate diet in adults with normal but not high body weight: A meta-analysis

BACKGROUND

Low-density lipoprotein (LDL) cholesterol change with consumption of a low-carbohydrate diet (LCD) is highly variable. Identifying the source of this heterogeneity could guide clinical decision-making.

OBJECTIVES

To evaluate LDL cholesterol change in randomized controlled trials involving LCDs, with a focus on body mass index (BMI) in kg/m2.

METHODS

Three electronic indexes (Pubmed, EBSCO, and Scielo) were searched for studies between 1 January, 2003 and 20 December, 2022. Two independent reviewers identified randomized controlled trials involving adults consuming <130 g/d carbohydrate and reporting BMI and LDL cholesterol change or equivalent data. Two investigators extracted relevant data, which were validated by other investigators. Data were analyzed using a random-effects model and contrasted with results of pooled individual participant data.

RESULTS

Forty-one trials with 1379 participants and a mean intervention duration of 19.4 wk were included. In a meta-regression accounting for 51.4% of the observed variability on LCDs, mean baseline BMI had a strong inverse association with LDL cholesterol change [β = -2.5 mg/dL/BMI unit, 95% confidence interval (CI): -3.7, -1.4], whereas saturated fat amount was not significantly associated with LDL cholesterol change. For trials with mean baseline BMI <25, LDL cholesterol increased by 41 mg/dL (95% CI: 19.6, 63.3) on the LCD. By contrast, for trials with a mean of BMI 25-<35, LDL cholesterol did not change, and for trials with a mean BMI ≥35, LDL cholesterol decreased by 7 mg/dL (95% CI: -12.1, -1.3). Using individual participant data, the relationship between BMI and LDL cholesterol change was not observed on higher-carbohydrate diets.

CONCLUSIONS

A substantial increase in LDL cholesterol is likely for individuals with low but not high BMI with consumption of an LCD, findings that may help guide individualized nutritional management of cardiovascular disease risk. As carbohydrate restriction tends to improve other lipid and nonlipid risk factors, the clinical significance of isolated LDL cholesterol elevation in this context warrants investigation. This trial was registered at PROSPERO as CRD42022299278.

Expert consensus on nutrition and lower-carbohydrate diets: An evidence- and equity-based approach to dietary guidance

There is a substantial body of clinical evidence supporting the beneficial effects of lower-carbohydrate dietary patterns on multiple established risk factors associated with insulin resistance and cardiovascular diseases in adult populations. Nutrition and health researchers, clinical practitioners, and stakeholders gathered for, "The Scientific Forum on Nutrition, Wellness, and Lower-Carbohydrate Diets: An Evidence- and Equity-Based Approach to Dietary Guidance" to discuss the evidence base around lower-carbohydrate diets, health outcomes, and dietary guidance. Consensus statements were agreed upon to identify current areas of scientific agreement and spotlight gaps in research, education, and practice to help define and prioritize future pathways. Given the evidence base and considering that most American adults are living with at least one nutrition-related chronic disease, there was consensus that including a lower-carbohydrate dietary pattern as one part of the Dietary Guidelines for Americans could help promote health equity among the general population.

Ketogenic diet and behavior: insights from experimental studies

As a journal page for full details. The ketogenic diet (KD) has been established as a treatment for epilepsy, but more recently it has been explored as an alternative or add-on therapy for many other diseases ranging from weight loss to neurological disorders. Animal models are widely used in studies investigating the therapeutic effects of the KD as well as underlying mechanisms. Especially in the context of neurological, psychiatric, and neurodevelopmental disorders essential endpoints are assessed by behavioral and motor tests. Here we summarized research evaluating the influence of the KD on cognition, depressive and anxiety-related behaviors, and social and nutritional behaviors of laboratory rodents. Each section contains a brief description of commonly used behavioral tests highlighting their limitations. Ninety original research articles, written in English, performed on mice or rats, providing measurement of blood beta-hydroxybutyrate (BHB) levels and behavioral evaluation were selected for the review. The majority of research performed in various disease models shows that the KD positively impacts cognition. Almost an equal number of studies report a reduction or no effect of the KD on depressive-related behaviors. For anxiety-related behaviors, the majority of studies show no effect. Despite the increasing use of the KD in weight loss and its appetite-reducing properties the behavioral evaluation of appetite regulation has not been addressed in preclinical studies. This review provides an overview of the behavioral effects of nutritional ketosis addressed to a broad audience of scientists interested in the KD field but not necessarily specializing in behavioral tests.

Avocado Consumption and Cardiometabolic Health: A Systematic Review and Meta-Analysis

BACKGROUND

Avocados are a rich source of unsaturated fats and bioactives, however, their role in altering cardiometabolic risk factors is unclear.

OBJECTIVE

The aim was to review the effects of consuming diets containing avocado compared with control diets containing no or low amounts of avocado on cardiometabolic risk factors in adults who were healthy, had clinical cardiovascular disease, or were at increased risk of cardiovascular disease.

METHODS

Five electronic databases were searched (PubMed, Web of Science, Scopus, ProQuest, and a Clinical Trials Registry) along with Google Scholar to identify studies published between January 1990 and November 10, 2021. Randomized controlled trials ≥3 weeks and prospective cohort studies were included. Ten studies-9 randomized controlled trials (n = 503 participants) and 1 prospective observational study (n = 55,407)-met the inclusion criteria. Outcomes assessed by means of meta-analysis were low-density lipoprotein cholesterol (LDL-C) (primary), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides. Outcomes assessed by narrative review were TC to HDL-C ratio, non-HDL-C, apolipoprotein B, blood pressure, body weight, body mass index (calculated as kg/m2), waist circumference, waist-to-hip ratio, body composition, and blood glucose and insulin concentrations. Risk of bias was assessed using the Cochrane Risk of Bias tool, version 2.0 and Newcastle-Ottawa Scale; quality of evidence was examined using the Grading of Recommendations, Assessment, Development and Evaluation method. Random-effects models meta-analyses were performed when there were ≥3 studies of the same design (ie, randomized controlled trial) and reporting the same outcome. Statistical heterogeneity was assessed by calculating χ2 and I2 statistics and publication bias was assessed by funnel plots.

RESULTS

Overall, there was a small, significant reduction in TC (-5.08 mg/dL [to convert to mmol/L, divide by 38.67]; 95% CI -9.29 to -0.87 mg/dL; P = .02) in avocado vs the control groups and no significant difference in LDL-C, HDL-C, or triglycerides. Subgroup analysis demonstrated significant reductions in LDL-C (-9.4 mg/dL [to convert to mmol/L, divide by 38.67]; 95% CI -10.84 to -7.95 mg/dL; P < .00001) and TC (-7.54 mg/dL; 95% CI -9.40 to -5.68 mg/dL; P < .00001) in avocado vs control groups in hypercholesterolemic populations, and no differences were seen in normocholesterolemic populations. However, the certainty in the findings was graded as low to very low. Body weight and composition were not negatively affected by avocado consumption.

CONCLUSIONS

Avocado consumption may reduce TC and LDL-C in people with hypercholesterolemia. Avocado consumption does not negatively impact body weight. Larger, well-conducted studies are needed to have greater confidence in the role of avocado consumption on cardiovascular disease risk factors.

Efficacy of convenience meal-type foods designed for diabetes in the management of metabolic syndrome based on a 3-week trial

OBJECTIVES

This study aimed to assess the effect of meal-type food for diabetes on improving metabolic syndrome risk factors in adults.

METHODS

The participants were adult men and women aged 40-55 y with 1 or more risk factors for metabolic syndrome. They were provided with a diabetic diet (a meal-type food) and general diet in the form of home meal replacement for 3 wk. The current research used a crossover design. All participants had iso-caloric meal replacement per day, and there was a 2-wk washout period between each diet. The nutritional standards of a diabetic diet were based on the guidelines of the Ministry of Food and Drug Safety, which are: <50% carbohydrates, <10% sugars, <7% saturated fat, and >10 g dietary fiber. The average caloric content was 489.1 ± 45.0 kcal. The composition of the general diet was similar to that of the diabetic diet; however, there were differences in sugar content. In total, 15 participants were included in the research, and there was no significant difference between the 2 groups in terms of nutrient intake during the intervention period.

RESULTS

Body weight (P = 0.001), body mass index (P = 0.004), waist circumference (P = 0.030), triacylglycerol (P = 0.002), total cholesterol (P = 0.001), and low-density lipoprotein cholesterol (P = 0.008) levels were significantly lower in the diabetic diet intervention period than before and after 3 wk of the intervention. In addition, reduction in body weight (P = 0.001), body mass index (P = 0.006), waist circumference (P = 0.032), and triacylglycerol (P = 0.036) and total cholesterol (P = 0.007) levels in the diabetic diet intervention period significantly differed compared with those in the general diet intervention period.

CONCLUSIONS

Replacing 1 meal per day with meal-type food for diabetes improved body composition and blood lipid levels in adults with metabolic syndrome risk factors.

A genomics perspective of personalized prevention and management of obesity

This review discusses the landscape of personalized prevention and management of obesity from a nutrigenetics perspective. Focusing on macronutrient tailoring, we discuss the impact of genetic variation on responses to carbohydrate, lipid, protein, and fiber consumption. Our bioinformatic analysis of genomic variants guiding macronutrient intake revealed enrichment of pathways associated with circadian rhythm, melatonin metabolism, cholesterol and lipoprotein remodeling and PPAR signaling as potential targets of macronutrients for the management of obesity in relevant genetic backgrounds. Notably, our data-based in silico predictions suggest the potential of repurposing the SYK inhibitor fostamatinib for obesity treatment in relevant genetic profiles. In addition to dietary considerations, we address genetic variations guiding lifestyle changes in weight management, including exercise and chrononutrition. Finally, we emphasize the need for a refined understanding and expanded research into the complex genetic landscape underlying obesity and its management.

Gut microbiota changes associated with low-carbohydrate diet intervention for obesity

Low-carbohydrate diets (LCDs) are frequently recommended for alleviating obesity, and the gut microbiota plays key roles in energy metabolism and weight loss. However, there is limited in-human research on how LCD changes gut microbiota. In this before-after study, 43 participants were assigned to the LCD intervention for 4 weeks. The main objective was to investigate the specific changes that occur in the participants' microbiome in response to the LCD. Changes in gut microbiota were analyzed using 16s rRNA sequencing. Body composition was measured using InBody 770. Remarkably, 35 participants (79.07%) lost more than 5% of their body weight; levels of BMI, body fat, and total cholesterol were significantly decreased, indicating the effectiveness of the LCD intervention. The richness of microbiota significantly increased after the intervention. By taking the intersection of ANOVA and linear discriminant analysis effect size (LEfSe) analysis results, we identified three phyla, three classes, four orders, five families, and six genera that were differentially enriched between baseline and week-4 time points. Among the three phyla, relative abundances of Firmicutes and Actinobacteriota decreased significantly, while Bacteroidetes increased significantly. At the genus level, Ruminococcus, Agathobacter, Streptococcus, and Bifidobacterium showed a significant reduction in relative abundances, whereas Parabacteroides and Bacteroides increased steadily. Our results demonstrate that LCD can effectively alleviate obesity and modify certain taxa of gut microbiota, providing potential insights for personalized dietary interventions against obesity.

Transcriptional and epigenetic changes after dietary and surgical weight loss interventions in an animal model of obesity

BACKGROUND

Identifying determinants that can predict response to weight loss interventions is imperative for optimizing therapeutic benefit. We aimed to identify changes in DNA methylation and mRNA expression of a subset of target genes following dietary and surgical interventions in high-fat-diet (HFD)-induced obese rats.

METHODS

Forty-two adult Wistar Han male rats were divided into two groups: control rats (n = 7) and obese rats (n = 28), fed a HFD for 10 weeks (t10). Obese rats were randomly subdivided into five intervention groups (seven animals per group): (i) HFD; (ii) very-low-calorie diet (VLCD); (iii) sham surgery, and (iv) sleeve gastrectomy (SG). At week sixteen (t16), animals were sacrificed and tissue samples were collected to analyze changes in DNA methylation and mRNA expression of the selected genes.

RESULTS

By type of intervention, the surgical procedures led to the greatest weight loss. Changes in methylation and/or expression of candidate genes occurred proportionally to the effectiveness of the weight loss interventions. Leptin expression, increased sixfold in the visceral fat of the obese rats, was partially normalized after all interventions. The expression of fatty acid synthase (FASN) and monocyte chemoattractant protein 1 (MCP-1) genes, which was reduced 0.5- and 0.15-fold, respectively, in the liver tissue of obese rats, were completely normalized after weight loss interventions, particularly after surgical interventions. The upregulation of FASN and MCP-1 gene expression was accompanied by a significant reduction in promoter methylation, up to 0.5-fold decrease in the case of the FASN (all intervention groups) and a 0.8-fold decrease in the case of the MCP-1 (SG group).

CONCLUSIONS

Changes in tissue expression of specific genes involved in the pathophysiological mechanisms of obesity can be significantly attenuated following weight loss interventions, particularly surgery. Some of these genes are regulated by epigenetic mechanisms.

Association of dietary adherence and dietary quality with weight loss success among those following low-carbohydrate and low-fat diets: a secondary analysis of the DIETFITS randomized clinical trial

BACKGROUND

Eating a high-quality diet or adhering to a given dietary strategy may influence weight loss. However, these 2 factors have not been examined concurrently for those following macronutrient-limiting diets.

OBJECTIVE

To determine whether improvement in dietary quality, change in dietary macronutrient composition, or the combination of these factors is associated with differential weight loss when following a healthy low-carbohydrate (HLC) or healthy low-fat (HLF) diet.

DESIGN

Generally healthy adults were randomly assigned to HLC or HLF diets for 12 mo (n = 609) as part of a randomized controlled weight loss study. Participants with complete 24-h dietary recall data at baseline and 12-mo were included in this secondary analysis (total N = 448; N = 224 HLC, N = 224 HLF). Participants were divided into 4 subgroups according to 12-mo change in HEI-2010 score [above median = high quality (HQ) and below median = low quality (LQ)] and 12-mo change in macronutrient intake [below median = high adherence (HA) and above median = low adherence (LA) for net carbohydrate (g) or fat (g) for HLC and HLF, respectively]. Baseline to 12-mo changes in mean BMI were compared for those in HQ/HA, HQ/LA, LQ/HA subgroups with the LQ/LA subgroup within HLC and HLF.

RESULTS

For HLC, changes (95 % confidence level [CI]) in mean BMI were -1.15 kg/m2 (-2.04, -0.26) for HQ/HA, -0.30 (-1.22, 0.61) for HQ/LA, and -0.80 (-1.74, 0.14) for LQ/HA compared with the LQ/LA subgroup. For HLF, changes (95% CI) in mean BMI were -1.11kg/m2 (-2.10, -0.11) for HQ/HA, -0.26 (-1.26, 0.75) for HQ/LA, and -0.66 (-1.74, 0.41) for LQ/HA compared with the LQ/LA subgroup.

CONCLUSION

Within both HLC and HLF diet arms, 12-mo decrease in BMI was significantly greater in HQ/HA subgroups relative to LQ/LA subgroups. Neither HQ nor HA alone were significantly different than LQ/LA subgroups. Results of this analysis support the combination of dietary adherence and high-quality diets for weight loss.

CLINICAL TRIAL REGISTRY

clinicaltrials.gov (Identifier: NCT01826591).

Non-Pharmacological Approach to Diet and Exercise in Metabolic-Associated Fatty Liver Disease: Bridging the Gap between Research and Clinical Practice

This review provides a practical and comprehensive overview of non-pharmacological interventions for metabolic-associated fatty liver disease (MASLD), focusing on dietary and exercise strategies. It highlights the effectiveness of coffee consumption, intermittent fasting, and Mediterranean and ketogenic diets in improving metabolic and liver health. The review emphasizes the importance of combining aerobic and resistance training as a critical approach to reducing liver fat and increasing insulin sensitivity. Additionally, it discusses the synergy between diet and exercise in enhancing liver parameters and the role of gut microbiota in MASLD. The paper underscores the need for a holistic, individualized approach, integrating diet, exercise, gut health, and patient motivation. It also highlights the long-term benefits and minimal risks of lifestyle interventions compared to the side effects of pharmacological and surgical options. The review calls for personalized treatment strategies, continuous patient education, and further research to optimize therapeutic outcomes in MASLD management.

Effect of carbohydrate restriction on body weight in overweight and obese adults: a systematic review and dose-response meta-analysis of 110 randomized controlled trials

Introduction

Carbohydrate-restricted diets are one of the most effective dietary interventions for weight loss. However, the optimum carbohydrate intake for implementing the most effective weight-loss interventions is still being discussed. We aimed to determine the optimum carbohydrate intake for short- and long-term weight loss in adults with overweight and obesity.

Methods

We searched PubMed, Scopus, Web of Science, and CENTRAL from inception to May 2021 for randomized controlled trials examining the effect of a carbohydrate-restricted diet (≤45% of energy intake) as compared to a control diet (carbohydrate intake >45% of energy intake) on body weight in adults with overweight/obesity. A random-effects dose-response meta-analysis was conducted to calculate the mean difference for each 10% decrease in carbohydrate intake at the 6-month follow-up (1 to 6 months), 12-month follow-up (6 to 12 months), and follow-up longer than 12 months. The shape of the dose-dependent effects was also evaluated. The certainty of the evidence was rated using the GRADE approach. The minimal clinically important difference (MCID) threshold was defined as 5% weight loss (equal to 4.39 kg).

Results

A total of 110 trials were selected for the present meta-analysis. In the linear dose-response meta-analysis, each 10% decrease in carbohydrate intake reduced body weight by 0.64 kg (95% CI: -0.79 to -0.49; n = 101 trials with 4,135 participants, high-certainty evidence) at the 6-month follow-up and by 1.15 kg (95% CI: -1.61 to -0.69; 42 trials with 2,657 participants, moderate-certainty evidence) at the 12-month follow-up. Non-linear dose-response meta-analyses indicated a monotonic reduction in body weight with the decrease in carbohydrate intake, with the greatest reduction at 5% at the 6-month follow-up (mean difference 5%: -3.96 kg, 95% CI: -4.92 to -3.00) and 10% at the 12-month follow-up (mean difference 10%: -6.26 kg, 95% CI: -10.42 to -2.10). At follow-up longer than 12 months, dose-response analyses suggested a non-linear effect, wherein carbohydrate intakes higher than 40% and lower than 30% were not effective for weight loss.

Discussion

Carbohydrate restriction is an effective dietary strategy for important weight loss in adults with overweight and obesity. At 6-month and 12-month follow-ups, body weight decreased proportionally, more than the MCID threshold, along with the decrease in carbohydrate intake. At follow-up longer than 12 months, there was a non-linear effect, with the greatest reduction at 30% carbohydrate intake.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022315042.