The Low-Carbohydrate Diet: Short-Term Metabolic Efficacy Versus Longer-Term Limitations

Association of low carbohydrate diet score with the risk of type 2 diabetes in an Australian population: A longitudinal study

AIMS

We aimed to assess the association of a low carbohydrate diet score (LCD) with the incidence of type 2 diabetes (T2D) using Melbourne Collaborative Cohort Study (MCCS) data.

METHODS

Between 1990 and 1994, the MCCS recruited 41,513 people aged 40-69 years. The first and second follow-ups were conducted in 1995-1998 and 2003-2007, respectively. We analyzed data from 39,185 participants. LCD score was calculated at baseline as the percentage of energy from carbohydrate, fat, and protein. The higher the score the less percentage of carbohydrates contributed to energy intake. The association of LCD quintiles with the incidence of diabetes was assessed using modified Poisson regression, adjusted for lifestyle, obesity, socioeconomic and other confounders. Mediation of the association by adiposity (BMI) was assessed.

RESULTS

LCD was positively associated with diabetes risk. Higher LCD score (p for trend = 0.001) was associated with increased risk of T2D. Quintile 5 (38 % energy from carbohydrates) versus quintile 1 (55 % energy from carbohydrates) showed a 20 % increased diabetes risk (incidence risk ratio (IRR) = 1.20 (95 % CI: 1.05-1.37)). A further adjustment for BMI (Body Mass Index) and WHR (Waist-to-Hip-Ratio) eliminated the association. Mediation analysis demonstrated that BMI mediated 76 % of the LCD & diabetes association.

CONCLUSIONS

Consuming a low carbohydrate diet, reflected as a high LCD score, may increase the risk of T2D which is largely explained by obesity. Results highlight the need for further studies, including clinical trials investigating the effects of a low carbohydrate diet in T2D.

Complementary and alternative medicine use in migraine patients: results from a national patient e-survey

Object

This cross-sectional study aims to investigate migraineurs' preferred complementary and alternative medicine (CAM) types and the factors influencing their usage.

Materials and methods

An anonymous e-survey was distributed to Lithuanian Migraine Association members, and social media migraine support communities. The collected data consisted of demographic, migraine-related questions, personal qualities, CAM habits.

Results

470 respondents were analyzed. 95.96% were women with a median age of 37 (IQR 31, 44). The median duration of migraine was 17.5 years (IQR 10, 25) and the median headache severity was rated 8 (IQR 7, 10) out of 10. 68.90% of participants had one or more headache days per week. 71.49% of respondents were triptan users, 27.66% used medical prophylaxis, and 17.87% used monoclonal antibodies. 52.55% of respondents used CAM in the past 12 months. Physical activity (36.17%), dietary changes/fasting (27.02%), relaxation/meditation (26.60%) were the most used CAM types. Reasons for CAM use included dissatisfaction with conventional treatment effectiveness (42.51%), concerns about safety (48.18%) and adverse effects (37.25%). Factors associated with the decision to explore CAM included longer headache duration (p = 0.017, Mann-Whitney U test), frequent sick leaves (p < 0.001, Mann-Whitney U test), current preventive medication use (p = 0.016, chi-square test), positive views on CAM safety/naturality (p = 0.001/ p < 0.001, Mann-Whitney U test), belief of having a healthy diet (p < 0.001, chi-square test), food-related worries (p = 0.011, Mann-Whitney U test) and Big-five personality trait of openness to experience (p = 0.049, chi-square test). After logistic regression, the frequent need to take sick leaves, having a healthy diet, food-associated fears maintained statistical significance. CAM use was not associated with non-adherence to conventional medicine. 48.99% of CAM consumers disclosed CAM use to their doctors.

Conclusion

CAM is explored by a significant proportion of migraineurs, less than half communicate this to their doctors. In our sample, physical activity, dietary changes, and relaxation techniques were the most common. Many patients opted for CAM due to previously experienced side effects/ineffectiveness of conventional migraine treatment or the fear of potential harm from standard medication. Individual factors, such as openness of personality can be an important contributing factor.

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.

The association between multiple trajectories of macronutrient intake and the risk of new-onset diabetes in Chinese adults

BACKGROUND

The association between macronutrient intake and diabetes is unclear. We used data from the China Health and Nutrition Survey to explore the association between macronutrient intake trajectories and diabetes risk in this study.

METHODS

We included 6755 participants who did not have diabetes at baseline and participated in at least three surveys. The energy supply ratio of carbohydrate, protein, and fat was further calculated from dietary data; different macronutrient trajectories were determined using multitrajectory models; and multiple Cox regression models were used to evaluate the association between these trajectories and diabetes.

RESULTS

We found three multitrajectories: decreased low carbohydrate-increased moderate protein-increased high fat (DLC-IMP-IHF), decreased high carbohydrate-moderate protein-increased low fat (DHC-MP-ILF), and balanced-macronutrients (BM). Compared to the BM trajectory, DHC-MP-ILF trajectories were significantly associated with increased risk of diabetes (hazard ratio [HR]: 3.228, 95% confidence interval [CI]: 1.571-6.632), whereas no association between DLC-IMP-IHF trajectories and diabetes was found in our study (HR: 0.699, 95% CI: 0.351-1.392).

CONCLUSIONS

The downward trend of high carbohydrate and the increasing trend of low fat increased the risk of diabetes in Chinese adults.

Effectiveness of a combined lifestyle intervention for older people in long-term care: A randomized controlled trial

PURPOSE

Lifestyle medicine interventions combining physical, nutritional, and psychological components have been found effective in general older population. However, evidence from the long-term care (LTC) is scarce.

METHODS

We conducted a pragmatic, two-arm, parallel group, superiority randomized controlled trial. Residents living in a LTC facility for one or more years, able to discern and to express informed consent, and requiring nursing care were considered eligible. The three-months intervention combined bi-weekly physical exercise groups, a healthy diet, and weekly psychological wellbeing sessions. Patients of the control group were subjected to routine care. At the end of the study participants were assessed using Barthel Index, Katz Activities of Daily Living, and Tinetti scales.

RESULTS

A total of 54 patients with a mean age of 84 years took part to the study. Physical exercise and psychological wellbeing sessions were mostly attended by all the subjects of the intervention group. Both groups took less calories than planned in the diets; in addition, the intervention group showed a lower energy and carbohydrates intake than the control group. At the end of the study, the intervention group showed a significant improvement in the total scores of all the scales.

CONCLUSIONS

This intervention was effective in improving functionality in older people living in the LTC setting. Results were achieved in a short timeframe, likely due to synergistic interactions between components. However, a further exploration of underlying factors is needed, to better understand the barriers that hampered a complete intervention delivery in this context.

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.

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.

Does a Ketogenic Diet Have a Place Within Diabetes Clinical Practice? Review of Current Evidence and Controversies

Carbohydrate restriction has gained increasing popularity as an adjunctive nutritional therapy for diabetes management. However, controversy remains regarding the long-term suitability, safety, efficacy and potential superiority of a very low carbohydrate, ketogenic diet compared to current recommended nutritional approaches for diabetes management. Recommendations with respect to a ketogenic diet in clinical practice are often hindered by the lack of established definition, which prevents its capacity to be most appropriately prescribed as a therapeutic option for diabetes. Furthermore, with conflicted evidence, this has led to uncertainty amongst clinicians on how best to support and advise their patients. This review will explore whether a ketogenic diet has a place within clinical practice by reviewing current evidence and controversies.

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.

Popular Diets and Kidney Stones

Popular diets often influence dietary patterns, which have different implications for kidney stone risk. Despite the wide variety of popular diets, some general principles can be gleaned from investigating their potential impact on nephrolithiasis. Plant-based diets, including Dietary Approaches to Stop Hypertension, Mediterranean, flexitarian, and vegetarian diets, may protect against nephrolithiasis when they consist largely of unprocessed plant foods, while carbohydrate-restricted diets (including high-protein diets and the ketogenic diet) may raise kidney stone risk. Patients should be advised to consume a diet rich in whole plants, particularly fruits and vegetables, and minimize their consumption of animal proteins. Accompanying fruits and vegetables that are higher in oxalate content with more water and some dairy intake may also be useful. (We address the oxalate content of fruits and vegetables further below). Calcium consumption is an important component of decreasing the risk of kidney stones, as higher dietary calcium from dairy or nondairy sources is independently associated with lower kidney stone risk. Patients should also be advised to be conscious of fat intake, as fat in the intestinal lumen may complex with calcium and therefore increase urinary oxalate excretion. Finally, patients should avoid consumption of processed foods, which often contain added fructose and high sodium content, two factors that increase kidney stone risk.

Low- or moderate-carbohydrate calorie-restricted diets have similar effects on body composition and taekwondo performance after high-carbohydrate recovery meals

Low-carbohydrate (LC) diets are popular among general and athletic populations attempting to lose body mass. This study investigated the effect of a 7-day LC or moderate-carbohydrate (MC) calorie-restricted diet followed by 18-h recovery on body composition and taekwondo-specific performance. In this randomised cross-over study, 12 male taekwondo athletes consumed an LC (10% of carbohydrate, 41% of protein, 49% of fat, and 15.8 ± 0.4 kcal/kg/day) or an isocaloric MC diet (60% of carbohydrate, 30% of protein, and 10% of fat) for 7 days. The participants then consumed a carbohydrate-rich recovery dinner (39.2 ± 3.1 kcal/kg) followed by breakfast (6.2 ± 0.4 kcal/kg) in both the trials. Three repeated sprint ability (RSA) tests were conducted after breakfast. The taekwondo-specific reaction battery was administered before the first RSA test and after each RSA test. The participants experienced similar magnitudes of significant loss of body mass in the LC (-2.4 ± 1.7%) and MC (-2.3 ± 1.7%) trials. Fat mass and fat percentage significantly decreased in the MC trial but remained unchanged in the LC trial after body mass loss. Fat free mass was maintained in both the trials. The average and peak power in the RSA tests and the premotor reaction time were similar between the trials. The participants experienced significantly higher fatigue in the LC trial. In conclusion, both the diets can help athletes rapidly lose body mass while maintaining performance as long as an adequate amount of carbohydrate is consumed during the recovery period.

Association of sugar intake from different sources with incident dementia in the prospective cohort of UK Biobank participants

BACKGROUND

Dementia is a common disease with around 55 million cases worldwide. Therefore, dietary changes and lifestyle interventions are important approaches to delay the progress of a decline in cognitive function. The study aims to explore the association of various sources of free sugars (FS) and intrinsic sugars with dementia risk in the prospective population-based UK Biobank cohort.

METHODS

Sugar consumption was assessed in 186,622 UK Biobank participants with at least one web-based dietary questionnaire (Oxford WebQ). Over a mean follow-up of 10.6 (standard deviation 1.1) years, 1498 incident dementia cases occurred. The hazard ratios (HR) for incident dementia were assessed with Cox proportional hazard regression models including sugar intake from different sources as penalized cubic splines to allow for non-linear predictor effects.

RESULTS

The intake of FS and intrinsic sugar was significantly associated with dementia risk in a J-shaped fashion with the HR-nadir observed at 9% and 8% total energy (%E), respectively. FS in beverages were significantly associated with dementia risk in an ascending approximately linear way, whereas no significant association was found for FS in solids. Assessing beverage subtypes, FS in soda/fruit drinks, milk-based drinks and to a lesser extent in juice were significantly and positively related to dementia risk, whereas no association was found for FS in tea/coffee. The association between sugar subtype consumption and dementia risk remained consistent in most sensitivity analyses but changed from a J-shape to a more linear shape when the analysis was restricted to participants with at least two Oxford WebQs.

CONCLUSIONS

A linear-shaped association between sugar subtype intake and dementia risk is most consistently found for FS in beverages and more specifically for FS in soda/fruit drinks, as well as in milk-based drinks.

Overall, plant-based, or animal-based low carbohydrate diets and all-cause and cause-specific mortality: A systematic review and dose-response meta-analysis of prospective cohort studies

INTRODUCTION

In this study, we sought to summarize the associations between overall, plant-, and animal-based low carbohydrate diet (LCD) scores and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality from prospective cohort studies.

METHODS

We searched PubMed, Scopus, and Web of Science up to January 2022. We included prospective cohort studies that investigated the relationship between LCD-score and risk of overall, CVD, or cancer mortality. Two investigators assessed the studies for eligibility and extracted the data. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Ten studies, with 421022 participants, were included in the analysis. In the high-versus-low meta-analysis, overall (HR:1.05,95%CI:0.97, 1.13, I2 =72.0%) and animal-based LCD-scores (HR: 1.08, 95% CI: 0.97-1.21; I2 = 88.0%) were not associated with all-cause mortality, but plant-based LCD-score was associated with a risk reduction (HR:0.87, 95%CI:0.78,0.97; I2 = 88.4%). CVD mortality was not associated with overall, plant-, or animal-based LCD-scores. Overall (HR:1.14, 95%CI:1.05,1.24; I2 = 37.4%) and animal-based LCD scores (HR:1.16,95%CI:1.02,1.31; I2 = 73.7%) were associated with a higher risk of cancer mortality, while plant-based LCD-score was not. A U-shaped relationship was revealed between overall LCD-score and all-cause and CVD mortality. The shape of relationship between LCD and cancer mortality was a linear dose-response.

CONCLUSION

In conclusion, diets with a moderate carbohydrate content were associated with the lowest risk of all-cause and CVD mortality. If the sources of macronutrients that replaced carbohydrates were plant-based, the risk of all-cause mortality was reduced linearly with lower carbohydrate content. The risk of cancer mortality increased linearly with the increase in carbohydrate content. Considering the low certainty of evidence, more robust prospective cohort studies are suggested.

Metabolic-Associated Fatty Liver Disease and Insulin Resistance: A Review of Complex Interlinks

Metabolic-associated fatty liver disease (MAFLD) has now surpassed alcohol excess as the most common cause of chronic liver disease globally, affecting one in four people. Given its prevalence, MAFLD is an important cause of cirrhosis, even though only a small proportion of patients with MAFLD ultimately progress to cirrhosis. MAFLD suffers as a clinical entity due to its insidious and often asymptomatic onset, lack of an accurate and reliable non-invasive diagnostic test, and lack of a bespoke therapy that has been designed and approved for use specifically in MAFLD. MAFLD sits at a crossroads between the gut and the periphery. The development of MAFLD (including activation of the inflammatory cascade) is influenced by gut-related factors that include the gut microbiota and intactness of the gut mucosal wall. The gut microbiota may interact directly with the liver parenchyma (through translocation via the portal vein), or indirectly through the release of metabolic metabolites that include secondary bile acids, trimethylamine, and short-chain fatty acids (such as propionate and acetate). In turn, the liver mediates the metabolic status of peripheral tissues (including insulin sensitivity) through a complex interplay of hepatokines, liver-secreted metabolites, and liver-derived micro RNAs. As such, the liver plays a key central role in influencing overall metabolic status. In this concise review, we provide an overview of the complex mechanisms whereby MAFLD influences the development of insulin resistance within the periphery, and gut-related factors impact on the development of MAFLD. We also discuss lifestyle strategies for optimising metabolic liver health.

The Effects of the Mediterranean Diet on Health and Gut Microbiota

The Mediterranean Diet (MD) is plant-based and consists of multiple daily portions of vegetables, fruit, cereals, and olive oil. Although there are challenges with isolating the MD from the typical Mediterranean lifestyle and culture (including prolonged 'social' meals and siestas), much evidence supports the health benefits of the MD that include improved longevity, reduced metabolic risk of Diabetes Mellitus, obesity, and Metabolic Syndrome, reduced risk of malignancy and cardiovascular disease, and improved cognitive function. The MD is also associated with characteristic modifications to gut microbiota, mediated through its constituent parts (primarily dietary fibres, extra virgin olive oil, and polyunsaturated fatty acids [including ω-3]). These include enhanced growth of species that produce short-chain fatty acids (butyrate), such as Clostridium leptum and Eubacterium rectale, enhanced growth of Bifidobacteria, Bacteroides, and Faecalibacterium prausnitzii species, and reduced growth of Firmicutes and Blautia species. Such changes in gut microbiota are known to be associated favourably with inflammatory and oxidative status, propensity for malignancy and overall metabolic health. A key challenge for the future is to explore the extent to which the health benefits of the MD are mediated by such changes to gut microbiota. The MD confers both health and environmental benefits. Adoption of the MD should perhaps be encouraged and facilitated more generally and not just restricted to populations from Mediterranean regions. However, there are key challenges to this approach that include limited perennial availability of the constituent parts of the MD in some non-Mediterranean regions, intolerability of a high-fibre diet for some people, and potential cultural disconnects that juxtapose some traditional (including Western) diets with the MD.

Ketogenic Diet in Children and Adolescents: the Effects on Growth and Nutritional Status

The ketogenic diet is known to be a possible adjuvant treatment in several medical conditions, such as in patients with severe or drug-resistant forms of epilepsy. Its use has recently been increasing among adolescents and young adults due to its supposed weight-loss effect, mediated by lipolysis and lowered insulin levels. However, there are still no precise indications on the possible use of ketogenic diets in pediatric age for weight loss. This approach has also recently been proposed for other types of disorder such as inherited metabolic disorders, Prader-Willi syndrome, and some specific types of cancers. Due to its unbalanced ratio of lipids, carbohydrates and proteins, a clinical evaluation of possible side effects with a strict evaluation of growth and nutritional status is essential in all patients following a long-term restrictive diet such as the ketogenic one. The prophylactic use of micronutrients supplementation should be considered before starting any ketogenic diet. Lastly, while there is sufficient literature on possible short-term side effects of ketogenic diets, their possible long-term impact on growth and nutritional status is not yet fully understood, especially when started in pediatric age.

Clinical Evidence of Low-Carbohydrate Diets against Obesity and Diabetes Mellitus

The popularity of low-carbohydrate diets (LCDs) in the last few decades has motivated several research studies on their role in a variety of metabolic and non-morbid conditions. The available data of the results of these studies are put under the research perspective of the present literature review of clinical studies in search of the effects of LCDs on Obesity and Diabetes Mellitus. The electronic literature search was performed in the databases PubMed, Cochrane, and Embase. The literature search found seven studies that met the review's inclusion and exclusion criteria out of a total of 2637 studies. The included studies involved randomized controlled trials of at least 12 weeks' duration, in subjects with BMI ≥ 25 kg/m², with dietary interventions. The results of the study on the effects of LCDs on obesity showed their effectiveness in reducing Body Mass Index and total body fat mass. In addition, LCDs appear to cause drops in blood pressure, low-density lipoprotein (LDL), and triglycerides, and seem to improve high-density lipoprotein (HDL) values. Regarding the effectiveness of LCDs in Diabetes Mellitus, their effect on reducing insulin resistance and fasting blood glucose and HbA1c values are supported. In conclusion, the results suggest the critical role of LCDs to improve the health of people affected by obesity or diabetes.

Dietary patterns and cardiometabolic health: Clinical evidence and mechanism

For centuries, the search for nutritional interventions to underpin cardiovascular treatment and prevention guidelines has contributed to the rapid development of the field of dietary patterns and cardiometabolic disease (CMD). Numerous studies have demonstrated that healthy dietary patterns with emphasis on food-based recommendations are the gold standard for extending lifespan and reducing the risks of CMD and mortality. Healthy dietary patterns include various permutations of energy restriction, macronutrients, and food intake patterns such as calorie restriction, intermittent fasting, Mediterranean diet, plant-based diets, etc. Early implementation of healthy dietary patterns in patients with CMD is encouraged, but an understanding of the mechanisms by which these patterns trigger cardiometabolic benefits remains incomplete. Hence, this review examined several dietary patterns that may improve cardiometabolic health, including restrictive dietary patterns, regional dietary patterns, and diets based on controlled macronutrients and food groups, summarizing cutting-edge evidence and potential mechanisms for CMD prevention and treatment. Particularly, considering individual differences in responses to dietary composition and nutritional changes in organ tissue diversity, we highlighted the critical role of individual gut microbiota in the crosstalk between diet and CMD and recommend a more precise and dynamic nutritional strategy for CMD by developing dietary patterns based on individual gut microbiota profiles.

[Nutrition for diabetic patients (Update 2023)]

All patients with diabetes require individual and personalized nutritional consultation with professionals. The patient's needs should be the primary focus of the dietary therapy, taking their lifestyle and the type of diabetes into consideration. With the recommendations to the patient's diet, there need to be specific metabolic goals to reduce the disease's progression and to avoid long term health effects. Therefore, practical guidelines such as portion size and meal planning tips should be the main focus.According to the latest national and international standards, patients suffering from diabetes should have access to nutrition consulting and nutritional training. During consultation they can be supported on- how to manage their health condition and choosing food and beverage to improve their health.These practical recommendations sum up the latest literature on nutritional aspects of diabetes treatment.

Macronutrient intake: Hormonal controls, pathological states, and methodological considerations

A plethora of studies to date has examined the roles of feeding-related peptides in the control of food intake. However, the influence of these peptides on the intake of particular macronutrient constituents of food - carbohydrate, fat, and protein - has not been as extensively addressed in the literature. Here, the roles of several feeding-related peptides in controlling macronutrient intake are reviewed. Next, the relationship between macronutrient intake and diseases including diabetes mellitus, obesity, and eating disorders are examined. Finally, some key considerations in macronutrient intake research are discussed. We hope that this review will shed light onto this underappreciated topic in ingestive behavior research and will help to guide further scientific investigation in this area.

Medical nutrition therapy for gestational diabetes mellitus in Australia: What has changed in 10 years and how does current practice compare with best practice?

BACKGROUND

The present study aimed to report Australian dietetic practice regarding management of gestational diabetes mellitus (GDM) and to make comparisons with the findings from a 2009 survey of dietitians and with the Academy of Nutrition and Dietetics Evidence-Based Nutrition Practice Guidelines (NPG).

METHODS

Cross-sectional surveys were conducted in 2019 and 2009 of dietitians providing medical nutrition therapy (MNT) to women with GDM in Australia. The present study compares responses on demographics, dietetic assessment and interventions, and guideline use in 2019 vs. 2009.

RESULTS

In total, 149 dietitians (2019) and 220 (2009) met survey inclusion criteria. In both surveys >60% of respondents reported dietary interventions aiming for >45% energy from carbohydrate, 15%-25% energy from protein and 15%-30% energy from fat. Many variations in MNT found in 2009 continued to be evident in 2019, including the percentage of energy from carbohydrate aimed for (30%-65% in 2019 vs. 20%-75% in 2009) and the wide range in the recommended minimum daily carbohydrate intake (40-220 and 60-300 g). Few dietitians reported aiming for the NPG minimum of 175 g of carbohydrate daily in both surveys (32% in 2019 vs. 26% in 2009). There were, however, some significant increases in MNT consistent with NPG recommendations in 2019 vs. 2009, including the minimum frequency of visits provided (49%, n = 61 vs. 33%, n = 69; p < 0.001) and provision of gestational weight gain advice (59%, n = 95 vs. 40%, n = 195; p < 0.05).

CONCLUSIONS

Although many dietitians continue to provide MNT consistent with existing NPG, there is a need to support greater uptake, especially for recommendations regarding carbohydrate intake.

Carbohydrate Intake and Its Association With Dietary Acid Load in U.S. Adults: Results From a Cross-Sectional Study

Background: The safety profile of low-carbohydrate diets is controversial and poorly understood. We investigated the effects of low-moderate carbohydrate intake on dietary acid load (DAL), an emerging health risk factor and novel clinical marker associated with numerous adverse clinical outcomes. Methods: We used data from the National Health and Nutrition Examination Surveys to investigate how low-moderate carbohydrate intake quantitatively affects DAL (as assessed by PRAL and NEAP scores) and to contrast the results to DAL scores in individuals that meet carbohydrate intake recommendations. Results: We analyzed data from 23 825 individuals, of which 4891 consumed a low-moderate carbohydrate diet. Said individuals derived 37.84% of energy from carbohydrates, tended to be male, had a mean BMI of 28.47 kg/m2, and consumed significantly more energy from fat and protein ( P≤.01 for both) than individuals that met carbohydrate recommendations Low-moderate carbohydrate intake was associated with a significantly higher DAL. Mean PRALR, NEAPR, and NEAPF values were 26.12, 71.02, and 68.98 mEq/d, respectively. Multivariate regression revealed the highest DAL scores in individuals on a low-carbohydrate diet, obtaining <26% of energy from carbohydrates. Conclusions: Low-moderate carbohydrate intake is associated with increased DAL scores, which has been repeatedly associated with various health repercussions.

Effectiveness of low-carbohydrate diets for long-term weight loss in obese individuals: A meta-analysis of randomized controlled trials

AIM

To assess whether low-carbohydrate (LC) diets are associated with differences in weight loss and well-being in people with obesity, and their cardiovascular and renal safety.

MATERIALS AND METHODS

A meta-analysis of randomized controlled trials longer than 3 months, retrieved through an extensive search on MedLine and Embase databases, comparing weight loss with LC and control diets in people with body mass index (BMI) greater than 30 kg/m² , was conducted.

RESULTS

We retrieved 25 trials. Compared with controls, LC diets were associated with significant reduction of body weight at 3-4 (MD -2.59 [-3.93, -1.25] kg) and 6-8 months (MD -2.64 [-4.32, -0.95]), but no difference at 10-14 and 18-30 months, and significantly greater BMI reduction at 3-4 months (-1.66 [-2.70, -0.61] kg/m² ), but not at other time points. Because only four trials reported data on renal function and psychological variables, renal safety and impact on well-being could not be assessed. Differences in fasting plasma glucose at any time point were not statistically significant. No significant differences in total or LDL cholesterol or blood pressure were found in the long term, whereas a long-term reduction of triglycerides (23.26 [-45.53, -0.98] mg/dl at 18-30 months), and increase of HDL cholesterol (MD 4.94 [0.30, 9.57] mg/dl at 18-30 months), were observed.

CONCLUSION

LC diets are associated with greater short-term weight loss than non-carbohydrate-restricted diets and a longer term favourable effect on cardiovascular risk factors. Further evidence on long-term efficacy and renal safety is needed before LC diets can be recommended as the preferred diets in obese people.

Female Endurance Runners Have a Healthier Diet than Males-Results from the NURMI Study (Step 2)

Sex has been recognized to be an important indicator of physiological, psychological, and nutritional characteristics among endurance athletes. However, there are limited data addressing sex-based differences in dietary behaviors of distance runners. The aim of the present study is to explore the sex-specific differences in dietary intake of female and male distance runners competing at >10-km distances. From the initial number of 317 participants, 211 endurance runners (121 females and 90 males) were selected as the final sample after a multi-level data clearance. Participants were classified to race distance (10-km, half-marathon, marathon/ultra-marathon) and type of diet (omnivorous, vegetarian, vegan) subgroups. An online survey was conducted to collect data on sociodemographic information and dietary intake (using a comprehensive food frequency questionnaire with 53 food groups categorized in 14 basic and three umbrella food clusters). Compared to male runners, female runners had a significantly greater intake in four food clusters, including “beans and seeds”, “fruit and vegetables”, “dairy alternatives”, and “water”. Males reported higher intakes of seven food clusters, including “meat”, “fish”, “eggs”, “oils”, “grains”, “alcohol”, and “processed foods”. Generally, it can be suggested that female runners have a tendency to consume healthier foods than males. The predominance of females with healthy dietary behavior can be potentially linked to the well-known differences between females and males in health attitudes and lifestyle patterns.

Low-carbohydrate versus balanced-carbohydrate diets for reducing weight and cardiovascular risk

BACKGROUND

Debates on effective and safe diets for managing obesity in adults are ongoing. Low-carbohydrate weight-reducing diets (also known as 'low-carb diets') continue to be widely promoted, marketed and commercialised as being more effective for weight loss, and healthier, than 'balanced'-carbohydrate weight-reducing diets.

OBJECTIVES

To compare the effects of low-carbohydrate weight-reducing diets to weight-reducing diets with balanced ranges of carbohydrates, in relation to changes in weight and cardiovascular risk, in overweight and obese adults without and with type 2 diabetes mellitus (T2DM).

SEARCH METHODS

We searched MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection (Clarivate Analytics), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) up to 25 June 2021, and screened reference lists of included trials and relevant systematic reviews. Language or publication restrictions were not applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults (18 years+) who were overweight or living with obesity, without or with T2DM, and without or with cardiovascular conditions or risk factors. Trials had to compare low-carbohydrate weight-reducing diets to balanced-carbohydrate (45% to 65% of total energy (TE)) weight-reducing diets, have a weight-reducing phase of 2 weeks or longer and be explicitly implemented for the primary purpose of reducing weight, with or without advice to restrict energy intake.  DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts and full-text articles to determine eligibility; and independently extracted data, assessed risk of bias using RoB 2 and assessed the certainty of the evidence using GRADE. We stratified analyses by participants without and with T2DM, and by diets with weight-reducing phases only and those with weight-reducing phases followed by weight-maintenance phases. Primary outcomes were change in body weight (kg) and the number of participants per group with weight loss of at least 5%, assessed at short- (three months to < 12 months) and long-term (≥ 12 months) follow-up.

MAIN RESULTS

We included 61 parallel-arm RCTs that randomised 6925 participants to either low-carbohydrate or balanced-carbohydrate weight-reducing diets. All trials were conducted in high-income countries except for one in China. Most participants (n = 5118 randomised) did not have T2DM. Mean baseline weight across trials was 95 kg (range 66 to 132 kg). Participants with T2DM were older (mean 57 years, range 50 to 65) than those without T2DM (mean 45 years, range 22 to 62). Most trials included men and women (42/61; 3/19 men only; 16/19 women only), and people without baseline cardiovascular conditions, risk factors or events (36/61). Mean baseline diastolic blood pressure (DBP) and low-density lipoprotein (LDL) cholesterol across trials were within normal ranges. The longest weight-reducing phase of diets was two years in participants without and with T2DM. Evidence from studies with weight-reducing phases followed by weight-maintenance phases was limited. Most trials investigated low-carbohydrate diets (> 50 g to 150 g per day or < 45% of TE; n = 42), followed by very low (≤ 50 g per day or < 10% of TE; n = 14), and then incremental increases from very low to low (n = 5). The most common diets compared were low-carbohydrate, balanced-fat (20 to 35% of TE) and high-protein (> 20% of TE) treatment diets versus control diets balanced for the three macronutrients (24/61). In most trials (45/61) the energy prescription or approach used to restrict energy intake was similar in both groups. We assessed the overall risk of bias of outcomes across trials as predominantly high, mostly from bias due to missing outcome data. Using GRADE, we assessed the certainty of evidence as moderate to very low across outcomes.  Participants without and with T2DM lost weight when following weight-reducing phases of both diets at the short (range: 12.2 to 0.33 kg) and long term (range: 13.1 to 1.7 kg).  In overweight and obese participants without T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to 8.5 months (mean difference (MD) -1.07 kg, (95% confidence interval (CI) -1.55 to -0.59, I2 = 51%, 3286 participants, 37 RCTs, moderate-certainty evidence) and over one to two years (MD -0.93 kg, 95% CI -1.81 to -0.04, I2 = 40%, 1805 participants, 14 RCTs, moderate-certainty evidence); as well as change in DBP and LDL cholesterol over one to two years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one year (risk ratio (RR) 1.11, 95% CI 0.94 to 1.31, I2 = 17%, 137 participants, 2 RCTs, very low-certainty evidence).  In overweight and obese participants with T2DM: low-carbohydrate weight-reducing diets compared to balanced-carbohydrate weight-reducing diets (weight-reducing phases only) probably result in little to no difference in change in body weight over three to six months (MD -1.26 kg, 95% CI -2.44 to -0.09, I2 = 47%, 1114 participants, 14 RCTs, moderate-certainty evidence) and over one to two years (MD -0.33 kg, 95% CI -2.13 to 1.46, I2 = 10%, 813 participants, 7 RCTs, moderate-certainty evidence); as well in change in DBP, HbA1c and LDL cholesterol over 1 to 2 years. The evidence is very uncertain about whether there is a difference in the number of participants per group with weight loss of at least 5% at one to two years (RR 0.90, 95% CI 0.68 to 1.20, I2 = 0%, 106 participants, 2 RCTs, very low-certainty evidence).  Evidence on participant-reported adverse effects was limited, and we could not draw any conclusions about these.  AUTHORS' CONCLUSIONS: There is probably little to no difference in weight reduction and changes in cardiovascular risk factors up to two years' follow-up, when overweight and obese participants without and with T2DM are randomised to either low-carbohydrate or balanced-carbohydrate weight-reducing diets.

A Novel Multiphase Modified Ketogenic Diet: An Effective and Safe Tool for Weight Loss in Chinese Obese Patients

PURPOSE

The aim of the present study was to investigate the effect and safety of a multiphase modified ketogenic diet (MMKD) compared to beinaglutide treatment or lifestyle modification (LM) alone on weight loss in obese patients in China.

PATIENTS AND METHODS

The present study was conducted in adults with obesity who did not have diabetes with two phases as follows: a 4-week run-in phase to guide diet and exercise, followed by a 12-week intervention phase aiming to lose weight. All participants performed aerobic and resistance exercise, and they were free to select any one of three weight-loss strategies as follows: LM group, 12 weeks of hypocaloric balanced diet (HBD); MMKD group, two cycles of a multiphase diet with each cycle comprised of 2 weeks of ketogenic diet (KD), 2 weeks of transition diet and 2 weeks of HBD; and beinaglutide group, 12 weeks of HBD plus daily injection of beinaglutide (0.4 mg per day). Body weight, body composition and metabolic variables were measured before and after the 12 weeks of treatment.

RESULTS

All intervention strategies had significant weight loss, and the MMKD led to greater weight loss than LM (difference, -3.7 kg; 95% confidence interval [CI], -6.1 to -1.4; P = 0.001) but not beinaglutide (difference, -1.5 kg; 95% CI, -4.3 to 1.3; P = 0.587). Waist circumference (WC), fat mass, body fat percentage (BFP) and visceral fat area (VFA) were also significantly decreased, and the MMKD had a greater effect on these parameters than LM or beinaglutide. In addition, significant reductions in blood pressure and homoeostatic model assessment of insulin resistance (HOMA-IR) were observed in all three groups, but the MMKD resulted in the most significant improvement in insulin resistance. Almost no adverse events, except for two cases of dizziness, were observed in the MMKD group, which was significantly fewer events than the other two groups.

CONCLUSION

These findings demonstrated that the MMKD is an effective and safe treatment for weight loss, thus providing an additional option for obese Chinese patients.

Experience of participants with chronic pain in a pilot randomized clinical trial using a ketogenic diet

Aim: To report the experience of chronic pain participants after a well-formulated ketogenic diet (WFKD) or whole-food diet (WFD). The quantitative outcomes for this trial have been published separately (clinical trial registration number ACTRN12620000946910). Patients & methods: The experience of 24 participants was evaluated after 12 and 24 weeks of dietary intervention using survey responses and open questions. Results & conclusion: Retention rates for the WFKD and WFD groups were 93 and 89%, respectively. Average adherence to the WFKD was 82% and to the WFD was 87%. The WFKD enjoyment was rated at 66 and 81% for the WFD group. The ease of adhering to the diet varied more widely for the WFKD group. Barriers included knowledge integration, time management, navigating social food environments and emotional attachment to eliminated foods. Facilitators included structured support and coaching, and comprehensive learning materials. The WFKD was shown to be a feasible and effective treatment option for chronic pain.

The Carbohydrate Threshold in Pregnancy and Gestational Diabetes: How Low Can We Go?

The original nutrition approach for the treatment of gestational diabetes mellitus (GDM) was to reduce total carbohydrate intake to 33–40% of total energy (EI) to decrease fetal overgrowth. Conversely, accumulating evidence suggests that higher carbohydrate intakes (60–70% EI, higher quality carbohydrates with low glycemic index/low added sugars) can control maternal glycemia. The Institute of Medicine (IOM) recommends ≥175 g/d of carbohydrate intake during pregnancy; however, many women are consuming lower carbohydrate (LC) diets (<175 g/d of carbohydrate or <40% of EI) within pregnancy and the periconceptual period aiming to improve glycemic control and pregnancy outcomes. This report systematically evaluates recent data (2018–2020) to identify the LC threshold in pregnancy in relation to safety considerations. Evidence from 11 reports suggests an optimal carbohydrate range of 47–70% EI supports normal fetal growth; higher than the conventionally recognized LC threshold. However, inadequate total maternal EI, which independently slows fetal growth was a frequent confounder across studies. Effects of a carbohydrate intake <175 g/d on maternal ketonemia and plasma triglyceride/free fatty acid concentrations remain unclear. A recent randomized controlled trial (RCT) suggests a higher risk for micronutrient deficiency with carbohydrate intake ≤165 g/d in GDM. Well-controlled prospective RCTs comparing LC (<165 g/d) and higher carbohydrate energy-balanced diets in pregnant women are clearly overdue.

The Microbiota and the Gut-Brain Axis in Controlling Food Intake and Energy Homeostasis

Obesity currently represents a major societal and health challenge worldwide. Its prevalence has reached epidemic proportions and trends continue to rise, reflecting the need for more effective preventive measures. Hypothalamic circuits that control energy homeostasis in response to food intake are interesting targets for body-weight management, for example, through interventions that reinforce the gut-to-brain nutrient signalling, whose malfunction contributes to obesity. Gut microbiota-diet interactions might interfere in nutrient sensing and signalling from the gut to the brain, where the information is processed to control energy homeostasis. This gut microbiota-brain crosstalk is mediated by metabolites, mainly short chain fatty acids, secondary bile acids or amino acids-derived metabolites and subcellular bacterial components. These activate gut-endocrine and/or neural-mediated pathways or pass to systemic circulation and then reach the brain. Feeding time and dietary composition are the main drivers of the gut microbiota structure and function. Therefore, aberrant feeding patterns or unhealthy diets might alter gut microbiota-diet interactions and modify nutrient availability and/or microbial ligands transmitting information from the gut to the brain in response to food intake, thus impairing energy homeostasis. Herein, we update the scientific evidence supporting that gut microbiota is a source of novel dietary and non-dietary biological products that may beneficially regulate gut-to-brain communication and, thus, improve metabolic health. Additionally, we evaluate how the feeding time and dietary composition modulate the gut microbiota and, thereby, the intraluminal availability of these biological products with potential effects on energy homeostasis. The review also identifies knowledge gaps and the advances required to clinically apply microbiome-based strategies to improve the gut-brain axis function and, thus, combat obesity.