Obesity Energetics: Body Weight Regulation and the Effects of Diet Composition

The Impact of Different Nutritional Approaches on Body Composition in People Living with Obesity

PURPOSE OF REVIEW

This narrative review aimed to provide an overview of the current evidence on the impact of various nutritional strategies on body composition in people living with obesity (PLwO), with particular attention to fat mass (FM), fat-free mass (FFM), and fat distribution.

RECENT FINDINGS

Obesity is increasingly linked to cardiometabolic complications, yet common diagnostic metrics such as body mass index (BMI) do not capture changes in FM or FFM. Recent studies highlight the variable effects of different dietary interventions on body compartments. High-protein and ketogenic diets are associated with greater preservation of FFM and reductions in visceral adipose tissue (VAT), while the Mediterranean diet shows promise for long-term adherence and improvements in metabolic health. Intermittent fasting and time-restricted eating demonstrate efficacy in FM reduction but present mixed results regarding FFM retention and sustainability. Dietary strategies exert diverse effects on body composition in PLwO, underscoring the importance of tailoring interventions to individual metabolic profiles and health goals. Personalized nutrition approaches that prioritize the preservation of lean mass and reduction of VAT, along with sustainable adherence, are critical for optimizing obesity management beyond weight loss alone.

Impact of other macronutrient composition within high-protein diet on body composition and cardiometabolic health: a systematic review, pairwise, and network meta-analysis of randomized controlled trials

BACKGROUND/OBEJCTIVE

Although the high-protein diets (HPDs) on weight control and body composition management are well investigated, mix results have been reported across studies and this variability may be attributed to differences in the composition of other macronutrients within HPDs. The aim of this study was to evaluate the impacts of HPDs with varied macronutrient compositions on body composition and cardiometabolic health outcomes through a systematic review, pairwise, and network meta-analysis.

METHODS

A comprehensive search of four databases (PubMed, Embase, CINAHL, and Web of Science) was conducted to identify relevant randomized controlled trials. A total of 83 articles were selected for systematic review and both meta-analyses.

RESULTS

Significant reduction in body mass (BM) (standardized mean difference [SMD] = -0.25; 95% CI: -0.40, -0.11), body mass index (BMI) (SMD = -0.26; 95% CI: -0.38, -0.15), waist circumference (WC) (SMD = -0.19; 95% CI: -0.33, -0.04), fat mass (FM) (mean difference [MD] = -0.64 kg; 95% CI: -0.98, -0.29), along with increase in lean body mass (LBM) (MD = 0.34 kg; 95% CI: 0.11, 0.57) were observed with HPDs regiments compared to normal-protein diets. Specifically, the high-protein, moderate-carbohydrate and high-fat diet ranked the best in reducing BM, BMI, WC, FM, systolic blood pressure, diastolic blood pressure and increasing LBM; while the high-protein, low-carbohydrate and high-fat diet obtained the highest score in reducing triglyceride and increasing high-density lipoprotein cholesterol.

CONCLUSION

HPDs effectively reduce FM and increase LBM, and offers potential cardiometabolic benefits. Additionally, the manipulation of carbohydrate content in HPDs may further influence these outcomes.

REGISTRATION

PROSPERO (CRD42023483907).

Metabolic profile of healthy, normal-weight adults with low satiety responsiveness

The aim of this study was to characterize the metabolic profile of healthy, normal-weight adults presenting with low satiety responsiveness. Individuals were categorized with low or high satiety responsiveness (LSR and HSR, respectively) based on the satiety quotient (SQ), a marker of satiety responsiveness, which was calculated following two isocaloric breakfast test meals offered while participants were inside the whole-room indirect calorimeter (WRIC): 1) North American: 55 % carbohydrate, 15 % protein, and 30 % fat; 2) High-protein: 31 % carbohydrate, 43 % protein, and 26 % fat. Following the North American breakfast, participants continued receiving a diet resembling the North American dietary pattern while inside the WRIC for 32 consecutive hours where the following outcome measures were assessed: energy metabolism components, metabolic blood markers, and appetite sensations. Forty-three participants were included; 13 were classified as LSR (n = 3 females; n = 10 males), n = 16 as HSR (n = 10 females; n = 6 males), and n = 14 were uncategorized. Compared with HSR, individuals with LSR had higher body weight (5.4 ± 2.5 kg; P = 0.042) and waist circumference (LSR: 77.5 (7.6) cm; HSR: 70.7 (5.2) cm; P = 0.012). Participants with LSR presented with higher total energy expenditure (184 ± 85 kcal/day; P = 0.040) and carbohydrate oxidation rate (34 ± 13 g/day; P = 0.015). Moreover, individuals in the LSR category presented with weakened satiety response to the meals when compared to those with HSR. Our primary findings were that, compared to individuals with HSR, those in the LSR category exhibited differences in their metabolic profile. The long-term impact on body weight and overall health should be assessed in further studies.

Low-Carbohydrate Diets for the Management of Pediatric Obesity: A Systematic Review and Meta-analysis

CONTEXT

Although low-carbohydrate (LC) diets have been shown to be beneficial for weight loss and improvements in cardiometabolic health in adults with obesity, their efficacy in youth has not yet been established.

OBJECTIVES

A systematic review and meta-analysis was conducted to qualitatively and quantitively synthesize the evidence from clinical trials testing the efficacy of LC diets to improve anthropometric and cardiometabolic-related parameters in children and adolescents with obesity.

DATA SOURCES

Searches in Medline, EMBASE, and Cochrane databases were undertaken for LC interventions with or without control comparisons.

DATA EXTRACTION AND ANALYSIS

Data before and after the LC intervention and control comparisons (if applicable) were extracted from 19 studies, 17 of which were pooled in random-effects meta-analyses.

RESULTS

Children on LC diets (Mean = 30 [IQR: 30-60] g/d), for approximately 3 months (IQR: 3-4 months) significantly reduced their weight (mean change [MC] = -7.09 [95% CI: -9.60, -4.58] kg; P < .001), body mass index (BMI) (MC = -3.01 [-3.71, -2.30] kg/m2; P < .001), and BMI z-score (MC = -0.27 [-0.48, -0.06]; P = .020), on average, with concomitant improvements in different metabolic biomarkers, such as serum triglycerides (MC = -29.16 [-45.06, -13.26] mg/dL; P = .002) and insulin (MC = -7.13 [-9.27, -4.99] µU/mL; P < .001). Evidence from 5 out of 7 controlled trials suggests that LC diets without caloric restriction may lead to similar or greater improvements in anthropometric and lipid-related outcomes relative to caloric-restricted or low-fat diets. However, meta-analyses demonstrated high between-study heterogeneity, indicative of a wide variety of methodologies, including intervention duration and degree of carbohydrate restriction.

CONCLUSION

Overall, this review found that short-term LC diets can be beneficial for weight loss and improving cardiometabolic parameters with or without calorie restriction. However, the limited number of controlled trials and the demonstrable diversity in methods prevent firm conclusions regarding their efficacy relative to traditional approaches, such as energy restriction.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023440835.

Resting metabolic rate and energy efficiency in response to an intensive 84-day combat-swimmer training in the German Armed Forces

PURPOSE

According to the 'constrained model', there are compensations in resting metabolic rate (RMR) at high levels of physical activity (PA). Here, we have used a standardized combat-swimmer training protocol (CST) to investigate whether changes in RMR (i) confirm the 'constraint model', and (ii) differ between successful participants and dropouts.

METHODS

Controlled 84d CST in 44 male soldiers with 13 finally successful. Fat mass (FM) and fat-free mass (FFM) were measured using Quantitative Magnetic Resonance. RMR was assessed by indirect calorimetry, VO2max, and work efficiency by treadmill spiroergometry. Plasma levels of thyroid hormones, testosterone, and cortisol were analysed by standard laboratory methods.

RESULTS

CST increased VO2max (+ 6.9%) and exercise efficiency at low workloads of 10 and 12 km/h (+ 8.7 and + 6.5%; both p < 0.05). As energy balance was moderately negative (-356 ± 383 kcal/d), FFM and FM decreased (-2 and -16%; both p < 0.05). There was a considerable inter-individual variance but no change in in the mean values of RMR and RMRadjFFM. RMRadjFFM before CST had a negative association with its decrease with CST (p < 0.005). Concomitantly, plasma hormone levels were unchanged. When compared with dropouts, successful participants had a higher VO2max at baseline (5.2 ± 0.6 vs. 4.9 ± 04 l/min; p < 0.05) that increased with CST (+ 4.4 vs. -0.4%; p < 0.05) at similar changes in body composition and energy balance.

CONCLUSION

While CST increased VO2max and exercise efficiency as a compensation, there was an inter-individual variance in exercise-related compensation of RMR with no differences between 'completers' and 'non-completers'. Trial registration DRKS00018850, November 27, 2019.

Impact of Individuals' Biological and Meals' Nutritional Characteristics on the Thermic Effect of Food in Humans: Meta-Regression of Clinical Trials

CONTEXT

The thermic effect of food (TEF) may be a therapeutic target for the prevention and treatment of obesity.

OBJECTIVE

The impact of different biological and nutritional characteristics on TEF in humans was analyzed.

DATA SOURCES

The MEDLINE/PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Latin American and Caribbean Health Sciences Literature databases were searched until November 2023 without language restrictions.

DATA EXTRACTION

Clinical trials were included that offered an oral test meal to adult and elderly individuals in a fasting state and measured TEF using calorimetry. The average TEF of each group was the outcome, and the impact of the individuals' and meal characteristics on the TEF was assessed using subgroups, meta-regression, and compositional analysis.

DATA ANALYSIS

The review included 133 studies, with 321 different groups. The mean TEF at 60 minutes after the test meal was 262 (95% CI, 236-288) kcal/d and decreased over time until 240 minutes after the test meal (P < .01). Male participants, individuals with normal body mass index, meals with energy content offered according to individual requirements, and meals with a mixed degree of food processing yielded a higher TEF. The total energy content of meals was the variable most strongly associated with TEF. Compositional analysis showed that the amount of lipids in meals was the only macronutrient consistently and negatively associated with TEF.

CONCLUSIONS

The TEF is influenced by specific individuals' and meal characteristics. Total energy content and the amount of lipids were the characteristics of the meals most consistently associated with TEF. However, due to important methodological differences between studies, it is difficult to determine how to use TEF as a potential therapeutic target against obesity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023432504.

Impact of dietary habit changes on college students physical health insights from a comprehensive study

College students' health and behavioral issues are gaining increasing global attention, with the optimization and choices of dietary structure becoming key factors affecting their physical and mental development. This study examines adolescents to explore the impact of dietary habit changes on their physical health. First, we investigated the factors influencing dietary habit changes after students entered college through questionnaires. Based on the theory of planned behavior, we constructed a structural equation model and found that perceived behavioral control had the greatest impact on college students' dietary choices. In addition, we investigated the patterns of dietary changes among adolescents and conducted an observational experiment on the impact of dietary changes on physical fitness. The results divided participants into three groups: those reducing high-calorie food intake, those increasing fiber intake, and those reducing high-fat and high-salt food intake. The findings showed that reducing high-calorie food intake had the most significant effect on students' physical health, resulting in a 7.5% improvement. Increasing fiber intake followed with a 5.68% improvement, while reducing high-fat and high-salt intake led to a 5.48% improvement in physical health. This study suggests that creating a supportive environment-within society, schools, and families-can encourage healthy eating habits among adolescents.

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.

Quinoa is more effective than other whole grains in the management of impaired glucose tolerance: a randomized controlled trial

The purpose of this study was to compare the effects of quinoa versus multigrain supplementation on glycemia and lipid metabolism among individuals with impaired glucose tolerance (IGT). In total, 207 participants diagnosed with IGT were randomly assigned to the quinoa group (QG; 100 g day-1, replacing about half of the total daily staple food), multiple whole grain group (WGG; 100 g day-1), or control group (CG) and followed for one year. Biomarkers were measured before and after the intervention. At the efficacy endpoint, the quinoa group (QG) demonstrated significantly longer time in range (TIR) and normal glucose tolerance (NGT) conversion rate, along with lower rates of 2-hour postprandial glucose (2hPG), fasting insulin (FINS), homeostatic model assessment of insulin resistance (HOMA-IR), 14-day mean blood glucose (14dMBG), and diabetes mellitus development compared to those of the multigrain and control groups (P < 0.05). Significant improvements in glycated hemoglobin (HbA1c) were also found in both the quinoa and multigrain groups compared to the control group (P < 0.05). No significant difference in glycemic variability (CV) was observed between the quinoa and control groups, while a significant difference was observed between the quinoa and multigrain groups (P < 0.05). These results suggest that quinoa consumption is significantly more effective than a multiple whole-grain diet in controlling IGT by reducing postprandial glucose and HbA1c levels, improving insulin resistance, and enhancing lipid profiles, making it a superior dietary choice for managing IGT.

When Should the Treatment of Obesity in Thyroid Disease Begin?

Obesity often coexists with thyroid diseases, and the prevalence of these disorders has been on the rise for years. While hypothyroidism can contribute to excess fat tissue, the relationship between Body Mass Index (BMI) and thyroid function hormones is bidirectional. Research confirms that fat tissue reduction can positively impact thyroid function. Thus, delaying the initiation of therapies beyond substitution treatment to achieve optimal weight reduction in individuals with thyroid dysfunction seems unwarranted. The authors summarize current knowledge on this topic in the article.

Regulation of energy balance by leptin as an adiposity signal and modulator of the reward system

BACKGROUND

Leptin is an adipose tissue-derived hormone that plays a crucial role in body weight, appetite, and behaviour regulation. Leptin controls energy balance as an indicator of adiposity levels and as a modulator of the reward system, which is associated with liking palatable foods. Obesity is characterized by expanded adipose tissue mass and consequently, elevated concentrations of leptin in blood. Leptin's therapeutic potential for most forms of obesity is hampered by leptin resistance and a narrow dose-response window.

SCOPE OF REVIEW

This review describes the current knowledge of the brain regions and intracellular pathways through which leptin promotes negative energy balance and restrains neural circuits affecting food reward. We also describe mechanisms that hinder these biological responses in obesity and highlight potential therapeutic interventions.

MAJOR CONCLUSIONS

Additional research is necessary to understand how pathways engaged by leptin in different brain regions are interconnected in the control of energy balance.

Integrated Insights into Metabolic and Bariatric Surgery: Improving Life Quality and Reducing Mortality in Obesity

Metabolic and bariatric surgery (MBS) is an effective intervention for patients with severe obesity and metabolic comorbidities, particularly when non-surgical weight loss methods prove insufficient. MBS has shown significant potential for improving quality of life and metabolic health outcomes in individuals with obesity, yet it carries inherent risks. Although these procedures offer a multifaceted approach to obesity treatment and its clinical advantages are well-documented, the limited understanding of its long-term outcomes and the role of multidisciplinary care pose challenges. With an emphasis on quality-of-life enhancements and the handling of postoperative difficulties, the present narrative review seeks to compile the most recent findings on MBS while emphasizing the value of an integrated approach to maximize patient outcomes. Effective MBS and patients' management require a collaborative team approach, involving surgeons, dietitians, psychologists, pharmacists, and other healthcare providers to address not only physiological but also psychosocial patient needs. Comparative studies demonstrate the efficacy of various MBS methods, including Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy that may considerably decrease morbidity and mortality in individuals with obesity. Future studies should target long-term patient treatment, and decision making should be aided by knowledge of obesity, comorbidity recurrence rates, and permanence of benefits.

Body mass as a result of psychological, lifestyle and genetic determinants. A pilot study involving overweight/obese and normal weight women in their early adulthood

AIM

The causes of obesity and overweight are complex and depend on mutually interrelated groups of lifestyle, psychological and genetic factors. Among 46 identified point mutations known within FTO gene, mutation SNP rs9939609 has the strongest effect on an increase in body weight. Therefore, the study aimed to assess psychological, lifestyle and genetic factors (expressed by the frequency of the FTO SNP rs-9939609 gene variant) and their association with body weight in young adult women.

METHODS

We genotyped FTO rs9939609 SNP in cheek swabs collected from 49 women aged 18-35, equally with and without overweight and obesity. Eating behaviour was defined based on the Questionnaire of Eating-Related Behaviors (QERB) and physical activity by the International Physical Activity Questionnaire (IPAQ). Classical anthropometric indices and the body composition analysis results measured by bioelectrical impedance were used to characterise nutritional status.

RESULTS

Overweight/obese participants had significantly higher body composition parameters than normal-weight participants, along with lower physical activity levels and more time spent sitting. Overweight/obese women presented significantly higher scores in emotional overeating, habitual overeating, and dietary restrictions, indicating more problematic eating behaviors compared to normal-weight individuals. No significant differences were observed in BMI, lifestyle factors, or eating behaviors across FTO gene variants (AA, AT, and TT). However, the TT and AT FTO gene variant groups showed significant positive correlations between habitual overeating and key measures of body weight (BMI, WC, and FM). In contrast, the AA variant group exhibited fewer associations between psychological and lifestyle factors with body weight.

CONCLUSIONS

Psychological and lifestyle factors, particularly overeating behaviors, were more strongly associated with increased body weight in women with the TT and AT variants of the FTO SNP rs-9939609 gene, highlighting the potential influence of genetic predisposition on eating habits and weight status in this population. Proper eating habits and high physical activity play an important role in preventing overweight and obesity regardless of the genotype that poses a potential risk of weight gain. The study's findings bring practical implications for health education and health psychology.

Testing a proposed mathematical model of weight loss in women enrolled on a commercial weight-loss programme: the LighterLife study

Weight loss results in obligatory reductions in energy expenditure (EE) due to loss of metabolically active fat-free mass (FFM). This is accompanied by adaptive reductions (i.e. adaptive thermogenesis) designed to restore energy balance while in an energy crisis. While the '3500-kcal rule' is used to advise weight loss in clinical practice, the assumption that EE remains constant during energy restriction results in a large overestimation of weight loss. Thus, this work proposes a novel method of weight-loss prediction to more accurately account for the dynamic trajectory of EE. A mathematical model of weight loss was developed using ordinary differential equations relying on simple self-reported inputs of weight and energy intake to predict weight loss over a specified time. The model subdivides total daily EE into resting EE, physical activity EE, and diet-induced thermogenesis, modelling obligatory and adaptive changes in each compartment independently. The proposed model was tested and refined using commercial weight-loss data from participants enrolled on a very low-energy total-diet replacement programme (LighterLife UK, Essex). Mathematical modelling predicted post-intervention weight loss within 0.75% (1.07 kg) of that observed in females with overweight or obesity. Short-term weight loss was consistently underestimated, likely due to considerable FFM reductions reported on the onset of weight loss. The best model agreement was observed from 6 to 9 weeks where the predicted end-weight was within 0.35 kg of that observed. The proposed mathematical model simulated rapid weight loss with reasonable accuracy. Incorporated terms for energy partitioning and adaptive thermogenesis allow us to easily account for dynamic changes in EE, supporting the potential use of such a model in clinical practice.

Quantitative analysis of the caloric restriction versus isocaloric diets models based on macronutrients composition: impacts on body weight regulation, anthropometric, and bioimpedance parameters in women with obesity

Introduction

Obesity is a growing public health issue, especially among young adults, with long-term management strategies still under debate. This prospective study compares the effects of caloric restriction and isocaloric diets with different macronutrient distributions on body composition and anthropometric parameters in obese women during a 12-week weight loss program, aiming to identify the most effective dietary strategies for managing obesity-related health outcomes.

Methods

A certified clinical nutritionist assigned specific diets over a 12-week period to 150 participants, distributed as follows: hypocaloric diets-low-energy diet (LED, 31 subjects) and very low-energy diet (VLED, 13 subjects); isocaloric diets with macronutrient distribution-low-carbohydrate diet (LCD, 48 subjects), ketogenic diet (KD, 23 subjects), and high-protein diet (HPD, 24 subjects); and isocaloric diet without macronutrient distribution-time-restricted eating (TRE, 11 subjects). Participants were dynamically monitored using anthropometric parameters: body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and bioelectrical impedance analysis (BIA) using the TANITA Body Composition Analyzer BC-418 MA III (T5896, Tokyo, Japan) at three key intervals-baseline, 6 weeks, and 12 weeks. The following parameters were evaluated: body weight, basal metabolic rate (BMR), percentage of total body fat, trunk fat, muscle mass, fat-free mass, and hydration status.

Results

All diets led to weight loss, but differences emerged over time. The TRE model resulted in significantly less weight loss compared to LED at the final follow-up (6.30 kg, p < 0.001), similar to the VLED (4.69 kg, p < 0.001). Isocaloric diets with varied macronutrient distributions showed significant weight loss compared to LED (p < 0.001). The KD reduced waist circumference at both 6 and 12 weeks (-4.08 cm, p < 0.001), while significant differences in waist-to-hip ratio reduction were observed across diet groups at 12 weeks (p = 0.01). Post-hoc analysis revealed significant fat mass differences at 12 weeks, with HPD outperforming IF (p = 0.01) and VLED (p = 0.003). LCD reduced trunk fat at 6 weeks (-2.36%, p = 0.001) and 12 weeks (-3.79%, p < 0.001). HPD increased muscle mass at 12 weeks (2.95%, p = 0.001), while VLED decreased it (-2.02%, p = 0.031). TRE showed a smaller BMR reduction at 12 weeks compared to LED.

Conclusion

This study highlights the superior long-term benefits of isocaloric diets with macronutrients distribution over calorie-restrictive diets in optimizing weight, BMI, body composition, and central adiposity.

Using stereotype violation to shift causal understanding and attitudes about weight

OBJECTIVE

We evaluated an approach to weight stigma reduction involving the provision of an exemplar inconsistent with belief systems underlying weight bias. Specifically, that people with higher weight eat unhealthy, high-calorie diets, and people with lower weight eat healthy, low-calorie diets. Providing exemplars that violate the stereotype's assumptions may lead to a change in beliefs, stereotypes, and ultimately, stigma.

METHODS

In an experimental, web-based study, 682 US-based participants were randomized to read narrative vignettes about a fictional middle-aged woman portrayed as either having stable, high body weight, or stable, low body weight, and as eating a long-term diet that was either high- or low- in calorie-dense foods. Two stereotype violation conditions involved a woman with higher weight who maintains a low-calorie diet (HWLC) and a woman with lower weight who maintains a high-calorie diet (LWHC).

RESULTS

For the HWLC exemplar, results were consistent with stereotype change processes including heightened genetic causal attributions, reduced lifestyle attributions, and more positive attitudes toward the exemplar and "women with obesity" in general. Response to the LWHC exemplar was more uneven.

CONCLUSIONS

Findings have implications in the understanding of judgments that people make about individuals based on their body size and dietary habits and suggests a new route for interventions that address weight stigma reduction.

Effects of high-protein supplementation during cancer therapy: a systematic review and meta-analysis

BACKGROUND

Establishing the effectiveness of high-protein supplementation in reducing cancer-related side effects is crucial.

OBJECTIVE

The study aimed to assess the effectiveness and safety of high-protein supplementation on clinical outcomes of patients undergoing cancer therapy.

METHODS

Systematic searches were conducted on Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Cochrane Central Register of Controlled Trials, and Scopus from inception until July 2023. Randomized controlled trials administering supplements with ≥10 g protein/serving, given to 20+ adult patients undergoing cancer therapy were included. Random-effects meta-analyses were used to estimate the effects of high-protein supplementation on the primary outcomes of body weight and health-related quality of life (HRQoL). We employed a vote-counting approach based on effect direction for secondary outcomes (that is, body composition, muscle function, hospitalization, response to cancer therapy/toxicity, survival, and systemic inflammation). Risk-of-bias (ROB) was assessed.

RESULTS

Thirty-five studies involving 3701 patients with diverse cancer types were included. Patients who received high-protein supplementation lost less body weight than controls (mean difference = 1.45 kg; 95% CI: 0.42, 2.48 kg; P = 0.006; I2 = 80%). No differences in HRQoL were observed; all studies assessing HRQoL were rated as high ROB. A beneficial effect on muscle mass was found in 11 of 13 studies, although most had a high ROB due to assessment techniques. When considering higher quality studies, evidence of a beneficial effect was found in 5 of 5 studies for muscle strength, and 3 of 4 for hospitalization rate. Effects on other secondary outcomes were inconsistent or limited. No serious adverse effects were reported.

CONCLUSIONS

High-protein supplementation mitigates weight loss, improves muscle strength, and lowers hospitalization rates in patients undergoing cancer therapy. These positive clinical outcomes, along with a favorable safety profile, suggest that high-protein supplementation may be a valuable addition to medical practice. However, given the need for more robust trials and the high ROB observed in the existing studies, these conclusions should be interpreted with caution. This review was prospectively registered with PROSPERO under the registration number CRD42021237372.

The vices and virtues of medical models of obesity

Despite numerous public health organizations supporting the pathologization of obesity and considering recent obesity rates a health crisis, many researchers in the humanities, social sciences, and even in the health sciences remain unconvinced. In this paper, we address a set of arguments coming from these academic fields that criticize medical models of obesity for their supposedly flawed diagnostic categories that shift focus onto individuals and support moralizing judgements. Clarifying some key claims in these models and explicating the view of obesity in terms of energy dysregulation, we aim to tease apart misunderstandings and argue that not only do these models not say what they are often accused of saying, but their apparent vices may actually be virtues in helping to combat stigma. Building on the social psychology of stigma and disease labeling, we then suggest that current medical models are largely supportive of many moral and political aims promoted by critics of these models.

Effect of Acupoint Catgut Embedding on Subjective Appetite in Overweight and Obese Adults with Strong and Moderate Appetite: A Secondary Analysis of a Randomized Clinical Trial

Background

Appetite plays a crucial role in obesity and weight loss outcomes. while conventional therapies reduce appetite, They often have limitations. Acupoint Catgut Embedding (ACE) is widely used for weight loss, but its impact on subjective appetite, especially across different appetite status, remains underexplored.

Objective

To evaluate the differential impact of ACE on the subjective appetite of overweight and obese adults with strong and moderate appetites.

Methods

This secondary analysis used data from a multicenter, double-blind, parallel randomized clinical trial of the ACE intervention. A total of 122 overweight and obese patients aged 18-60 were randomly assigned to the ACE and Non-acupoint Catgut Embedding (NACE) groups, each receiving six sessions over 12 weeks and a 4-week follow-up. Appetite was measured using the Visual Analogue Scale (VAS), and a generalized linear mixed-effects model assessed changes in appetite scores. Bonferroni corrections were applied for multiple comparisons (P < 0.05).

Results

Participants with strong appetite in the ACE group showed a significant reduction in appetite VAS score from 7.78 (0.66) at baseline to 5.00 (0.72) at 16 weeks (P < 0.05), compared to a reduction from 7.97 (0.93) to 6.54 (1.17) in the NACE group. The adjusted relative rate ratio between the two groups was 0.411 (95% CI, 0.210 to 0.534; P < 0.05). In participants with moderate appetite, no significant difference was observed between the two groups (P > 0.05). The significant baseline difference in appetite scores between participants with strong and moderate appetite (P < 0.05) became non-significant by week 16 (P > 0.05).

Conclusion

This study reveals the stratified effect of ACE on appetite, with greater reduction in those with strong appetite and no significant change in those with moderate appetite. This suggests ACE reduces appetite effectively without excessive suppression, supporting its potential as a sustainable obesity management strategy.

Dietary habit and risk of rheumatoid arthritis: a mendelian randomization study identifying protective and risk factors

PURPOSE

Dietary habit significantly contributes to the initiation and progression of rheumatoid arthritis (RA). Dietary choices intersect with a range of clinical and societal factors. The utilization of cross-sectional methodologies in numerous studies poses a challenge in establishing definitive causality for the noted associations. Moreover, within identical food categories, specific items may elicit diverse effects on the pathogenesis of RA, and the correlation between several prevalent food items or beverages and RA remains inadequately explored.

METHODS

We performed a two-sample Mendelian Randomization (MR) study to evaluate the causal impact of 27 distinct dietary habits and RA susceptibility. These dietary-related phenotypes encompass both the relative intake of the four macronutrients (fat, protein, carbohydrates, and sugar) and 23 specific single food intake. Several filtering steps were employed to select eligible genetic instruments strongly associated with each of the traits. The random-effects inverse-variance weighted, weighted median, and MR-Egger methods were employed for MR estimations. Sensitivity analyses and power calculations were executed to ensure the robustness of our study.

RESULTS

After rigorous single-nucleotide polymorphism (SNP) filtering procedures, 611 SNPs were included in our ongoing investigations. The consumption of dried fruit, bread, and alcohol emerged as protective factors, while beef, processed meat, and coffee intake were identified as risk factors. The robustness of our study was confirmed through the outcomes of sensitivity analysis and power calculation.

CONCLUSION

The ongoing investigations furnish evidence that accentuates the influence of diet on RA disease activity, underscoring the importance of delineating the optimal nutritional lifestyle for RA patients.

Energy expenditure, metabolic adaptation, physical activity and energy intake following weight loss: comparison between bariatric surgery and low-calorie diet

OBJECTIVE

Bariatric surgery remains the most effective treatment to achieve substantial weight loss; however, total daily energy expenditure and physical activity changes in response to such interventions have been seldom explored.

METHODS

In this prospective observational study, total daily energy expenditure (TDEE) using doubly labeled water and physical activity (SenseWear armband) was assessed in 17 females (mean ± SD: 48.6 ± 9.7 kg/m2, 43 ± 12 years) at baseline and 8 and 52 weeks following either bariatric surgery (BSG, N = 9) or a low-calorie diet (LCD, N = 8). Energy intake was assessed using the intake-balance method.

RESULTS

After 8 weeks, weight loss was 16.0 ± 3.5 kg and TDEE decreased by 552 ± 319 kcal/d in BSG (P < 0.001) compared to 8.8 ± 3.4 kg and 256 ± 239 kcal/d in LCD (P < 0.05). After 52 weeks, weight loss was 44.3 ± 16.4 kg and TDEE decreased by 583 ± 418 kcal/d (P < 0.001), compared to 4.3 ± 6.7 kg and 84 ± 285 kcal/d in LCD (P > 0.05). TDEE was lower than predicted in BSG at 8 (P = 0.03) but not 52 weeks (P = 0.77). There was no evidence of metabolic adaptation in LCD. Average daily energy intake in BSG was 1403 ± 245 kcal/d compared to 2545 ± 398 kcal/d in LCD (P < 0.001). In BSG, step count and physical activity minutes were increased at 52 weeks compared to baseline (P = 0.03), whereas no significant changes were observed in LCD.

CONCLUSION

Bariatric surgery-induced weight loss decreased TDEE at 8 weeks and 1 year, resulting in metabolic adaptation after 8 weeks that was reversed at 1 year. These changes were accompanied by an increase in physical activity.

Effects of Specially Designed Energy-Restricted Diet on Anthropometric Parameters and Cardiometabolic Risk in Overweight and Obese Adults: Pilot Study

BACKGROUND/AIMS

This study examined the effects of a specially designed energy-restricted diet with alternate carbohydrate intake on body composition and cardiometabolic risk factors in overweight and obese adults. The aim was to assess whether the intervention could lead to significant weight loss, improve body composition, and reduce cardiometabolic risks.

METHODS

Sixty-five participants (34 women, 31 men) with an average BMI of 31.8 ± 9.1 kg/m2 (women) and 34.1 ± 6.4 kg/m2 (men) participated in a 14-week intervention. The diet included different days of carbohydrate intake and a 20% reduction in total daily energy consumption. Anthropometric measurements and biochemical parameters, including predictive indices of cardiometabolic risk, were determined at baseline and after the intervention.

RESULTS

The intervention resulted in a significant reduction in body weight (mean weight loss of 17%, p < 0.001), with 64.6% of participants achieving a weight loss of at least 10%. Muscle mass as a percentage of total body weight increased. Cardiometabolic improvements were observed in fasting blood glucose (from 5.4 to 4.9 mmol/L, p < 0.001) and LDL cholesterol (from 3.38 to 2.81 mmol/L, p < 0.001). Gender-specific differences were found, particularly in HDL-C, which decreased significantly in women (p = 0.013), while there was a non-significant increase in men. Cardiometabolic indices, including the Visceral Adiposity Index (VAI) and the Cardiometabolic Index (CMI), also improved significantly.

CONCLUSIONS

The alternate carbohydrate diet improved body composition, cardiometabolic health, and treatment adherence through metabolic flexibility. However, the short duration of this study and the lack of a control group suggest that further research is needed to assess long-term sustainability.

Diet and physical exercise as key players to tackle MASLD through improvement of insulin resistance and metabolic flexibility

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) has emerged as a prevalent health concern, encompassing a wide spectrum of liver-related disorders. Insulin resistance, a key pathophysiological feature of MASLD, can be effectively ameliorated through dietary interventions. The Mediterranean diet, rich in whole grains, fruits, vegetables, legumes, and healthy fats, has shown promising results in improving insulin sensitivity. Several components of the Mediterranean diet, such as monounsaturated fats and polyphenols, exert anti-inflammatory and antioxidant effects, thereby reducing hepatic steatosis and inflammation. Furthermore, this dietary pattern has been associated with a higher likelihood of achieving MASLD remission. In addition to dietary modifications, physical exercise, particularly resistance exercise, plays a crucial role in enhancing metabolic flexibility. Resistance exercise training promotes the utilization of fatty acids as an energy source. It enhances muscle glucose uptake and glycogen storage, thus reducing the burden on the liver to uptake excess blood glucose. Furthermore, resistance exercise stimulates muscle protein synthesis, contributing to an improved muscle-to-fat ratio and overall metabolic health. When implemented synergistically, the Mediterranean diet and resistance exercise can elicit complementary effects in combating MASLD. Combined interventions have demonstrated additive benefits, including greater improvements in insulin resistance, increased metabolic flexibility, and enhanced potential for MASLD remission. This underscores the importance of adopting a multifaceted approach encompassing dietary modifications and regular physical exercise to effectively manage MASLD. This narrative review explores the biological mechanisms of diet and physical exercise in addressing MASLD by targeting insulin resistance and decreased metabolic flexibility.

Ketogenic diet but not free-sugar restriction alters glucose tolerance, lipid metabolism, peripheral tissue phenotype, and gut microbiome: RCT

Restricted sugar and ketogenic diets can alter energy balance/metabolism, but decreased energy intake may be compensated by reduced expenditure. In healthy adults, randomization to restricting free sugars or overall carbohydrates (ketogenic diet) for 12 weeks reduces fat mass without changing energy expenditure versus control. Free-sugar restriction minimally affects metabolism or gut microbiome but decreases low-density lipoprotein cholesterol (LDL-C). In contrast, a ketogenic diet decreases glucose tolerance, increases skeletal muscle PDK4, and reduces AMPK and GLUT4 levels. By week 4, the ketogenic diet reduces fasting glucose and increases apolipoprotein B, C-reactive protein, and postprandial glycerol concentrations. However, despite sustained ketosis, these effects are no longer apparent by week 12, when gut microbial beta diversity is altered, possibly reflective of longer-term adjustments to the ketogenic diet and/or energy balance. These data demonstrate that restricting free sugars or overall carbohydrates reduces energy intake without altering physical activity, but with divergent effects on glucose tolerance, lipoprotein profiles, and gut microbiome.

The effects of dietary macronutrient composition on resting energy expenditure following active weight loss: A systematic review and meta-analysis

A systematic review and meta-analysis was conducted to evaluate the relative effectiveness of different dietary macronutrient patterns on changes in resting energy expenditure (REE) in relation to weight loss, categorized as minimal (<5%) and moderate to high (>5%). Changes in REE were assessed using a DerSimonian and Laird random-effects meta-analysis. A diet lower in carbohydrates (CHO) or higher in fat and protein was associated with smaller reductions in REE, with these trends being more pronounced among participants who experienced moderate to high weight loss. Adjusted meta-regression analysis indicated that, within the participants who experienced moderate to high weight loss, each 1% increase in CHO intake was associated with a reduction of 2.30 kcal/day in REE (95% CI: -4.11 to -0.47, p = 0.013). In contrast, a 1% increase in protein and fat intake was correlated with an increase in REE by 3.00 (95% confidence interval [CI] [1.02, 5.07], p = 0.003) and 0.5 (95% CI [-2.43, 3.41], p = 0.740) kcal/day, respectively. No significant associations were found among participants who experienced minimal weight loss. These findings indicate that, under a caloric deficit, the impact of dietary macronutrient composition on REE may vary depending on the degree of weight loss and individual metabolic responses.

Cellular Senescence and Extracellular Vesicles in the Pathogenesis and Treatment of Obesity-A Narrative Review

This narrative review explores the pathophysiology of obesity, cellular senescence, and exosome release. When exposed to excessive nutrients, adipocytes develop mitochondrial dysfunction and generate reactive oxygen species with DNA damage. This triggers adipocyte hypertrophy and hypoxia, inhibition of adiponectin secretion and adipogenesis, increased endoplasmic reticulum stress and maladaptive unfolded protein response, metaflammation, and polarization of macrophages. Such feed-forward cycles are not resolved by antioxidant systems, heat shock response pathways, or DNA repair mechanisms, resulting in transmissible cellular senescence via autocrine, paracrine, and endocrine signaling. Senescence can thus affect preadipocytes, mature adipocytes, tissue macrophages and lymphocytes, hepatocytes, vascular endothelium, pancreatic β cells, myocytes, hypothalamic nuclei, and renal podocytes. The senescence-associated secretory phenotype is closely related to visceral adipose tissue expansion and metaflammation; inhibition of SIRT-1, adiponectin, and autophagy; and increased release of exosomes, exosomal micro-RNAs, pro-inflammatory adipokines, and saturated free fatty acids. The resulting hypernefemia, insulin resistance, and diminished fatty acid β-oxidation lead to lipotoxicity and progressive obesity, metabolic syndrome, and physical and cognitive functional decline. Weight cycling is related to continuing immunosenescence and exposure to palmitate. Cellular senescence, exosome release, and the transmissible senescence-associated secretory phenotype contribute to obesity and metabolic syndrome. Targeted therapies have interrelated and synergistic effects on cellular senescence, obesity, and premature aging.

7-MEGA™ inhibits adipogenesis in 3T3-L1 adipocytes and suppresses obesity in high-fat-diet-induced obese C57BL/6 mice

BACKGROUND

Overweight, often known as obesity, is the abnormal and excessive accumulation of fat that exposes the health of a person at risk by increasing the likelihood that they may experience many chronic conditions. Consequently, obesity has become a global health threat, presenting serious health issues, and attracting a lot of attention in the healthcare profession and the scientific community.

METHOD

This study aims to explore the anti-adipogenic properties of 7-MEGA™ in an attempt to address obesity, using both in vitro and in vivo research. The effects of 7MEGA™ at three distinct concentrations were investigated in obese mice who were given a high-fat diet (HFD) and 3T3-L1 adipocytes.

RESULTS

7MEGA™ decreased the total fat mass, overall body weight, and the perirenal and subcutaneous white adipose tissue (PWAT and SWAT) contents in HFD mice. Additionally, 7MEGA™ showed promise in improving the metabolic health of individuals with obesity and regulate the levels of insulin hormone, pro-inflammatory cytokines and adipokines. Furthermore, Peroxisome proliferator-activated receptors (PPAR) α and γ, Uncoupling Protein 1 (UCP-1), Sterol Regulatory Element-Binding Protein 1 (SREBP-1), Fatty Acid-Binding Protein 4 (FABP4), Fatty Acid Synthase (FAS), Acetyl-CoA Carboxylase (ACC), Stearoyl-CoA Desaturase-1 (SCD-1) and CCAAT/Enhancer-Binding Protein (C/EBPα) were among the adipogenic regulators that 7MEGA™ could regulate.

CONCLUSION

In summary, this study uncovered that 7MEGA™ demonstrates anti-adipogenic and anti-obesity effects, suggesting its potential in combating obesity.

Plant foods, healthy plant-based diets, and type 2 diabetes: a review of the evidence

Type 2 diabetes (T2D) is a metabolic chronic disease in which insulin resistance and insufficient insulin production lead to elevated blood glucose levels. The prevalence of T2D is growing worldwide, mainly due to obesity and the adoption of Western diets. Replacing animal foods with healthy plant foods is associated with a lower risk of T2D in prospective studies. In randomized controlled trials, the consumption of healthy plant foods in place of animal foods led to cardiometabolic improvements in patients with T2D or who were at high risk of the disease. Dietary patterns that limit or exclude animal foods and focus on healthy plant foods (eg, fruits, vegetables, whole grains, nuts, legumes), known as healthy, plant-based diets, are consistently associated with a lower risk of T2D in cohort studies. The aim of this review is to examine the differential effects of plant foods and animal foods on T2D risk and to describe the existing literature about the role of healthy, plant-based diets, particularly healthy vegan diets, in T2D prevention and management. The evidence from cohort studies and randomized controlled trials will be reported, in addition to the potential biological mechanisms that seem to be involved.

Use of probiotics in preventing and treating excess weight and obesity. A systematic review

Background

The prevalence of excess weight and obesity is increasing in an extremely concerning manner worldwide, with highly diverse therapies for current treatment. This review evaluated the scientific evidence of the past 10 years on the use of probiotics in treating excess weight and obesity in the absence of dieting.

Materials

A systematic review was conducted by searching for clinical trials on humans published in English in the PubMed, Scopus and Cochrane Central databases, using the combination of keywords "Overweight", "Probiotics" and "Obesity", and published between 2012 and 2022.

Results

Six published studies met the inclusion criteria. The review showed that, although there is a lack of consensus in the literature, the use of probiotics in the absence of dieting produced a significant reduction in body weight and body mass index in 66.6% of the reviewed studies, a significant reduction in waist circumference in 80.0% of the reviewed studies, and an improvement in total body fat mass and waist circumference.

Conclusions

This review showed evidence of a trend in preventing body weight gain and reducing weight through the use of probiotics in individuals with excess weight or obesity. A combination of various strains of the genera Bifidobacterium and Lactobacillus was the most effective.

Dawn-to-dusk dry fasting decreases circulating inflammatory cytokines in subjects with increased body mass index

BACKGROUND

The circadian rhythm involves numerous metabolic processes, including sleep/awakening, body temperature regulation, hormone secretion, hepatic function, cellular plasticity, and cytokine release (inflammation), that appear to have a dynamic relationship with all the processes above. Studies have linked various cytokines to the chronic state of low-grade inflammation and oxidative stress in obesity. Dawn-to-dusk dry fasting (DDDF) could alleviate the adverse effects of obesity by decreasing inflammation. This study examined the effects of DDDF on circulating inflammatory cytokines in subjects with increased body mass index (BMI).

METHODS

The current observational prospective study included adult subjects with a BMI equal to or greater than 25 kg/m2 who practiced the annual religious 30-day DDDF. Individuals with significant underlying medical conditions were excluded to limit confounding factors. All subjects were evaluated within two weeks before 30-day DDDF, within the fourth week of 30-day DDDF, and within two weeks after 30-day DDDF. Multiple cytokines and clinical health indicators were measured at each evaluation.

RESULTS

Thirteen subjects (10 men and three women) with a mean age of 32.9 years (SD = 9.7 years) and a mean BMI of 32 kg/m2 (SD = 4.6 kg/m2) were included. An overall associated decrease in the levels of multiple cytokines with DDDF was observed. A significant decrease in the mean interleukin 1 beta level was observed within the fourth week of 30-day DDDF (P = 0.045), which persisted even after the fasting period (P = 0.024). There was also a significant decrease in the mean levels of interleukin 15 (IL-15) (P = 0.014), interleukin 1 receptor antagonist (P = 0.041), macrophage-derived chemokine (MDC) (P = 0.013), and monokine induced by interferon gamma/chemokine (C-X-C motif) ligand 9 (P = 0.027) within the fourth week of 30-day DDDF and in the mean levels of fibroblast growth factor 2 (P = 0.010), interleukin 12 p40 subunit (P = 0.038), interleukin 22 (P = 0.025) and tumor necrosis factor alpha (P = 0.046) within two weeks after 30-DDDF. In terms of anthropometric parameters, there was a decrease in mean body weight (P = 0.032), BMI (P = 0.028), and hip circumference (P = 0.007) within the fourth week of 30-day DDDF and a decrease in mean weight (P = 0.026), BMI (P = 0.033) and hip circumference (P = 0.016) within two weeks after 30-day DDDF compared with the levels measured within two weeks before 30-day DDDF. Although there was no significant correlation between changes in weight and changes in circulating inflammatory cytokines, there was a significant positive correlation between changes in waist circumference and changes in specific inflammatory cytokines (e.g., IL-15, MDC, platelet-derived growth factor, soluble CD40L, vascular endothelial growth factor A) within the fourth week of 30-day DDDF and/or two weeks after 30-day DDDF. A significant decrease in mean average resting heart rate within the fourth week of 30-day DDDF was also observed (P = 0.023), and changes between average resting heart rate and changes in interleukin-8 levels within the fourth week of 30-day DDDF compared with baseline levels were positively correlated (r = 0.57, P = 0.042).

CONCLUSION

DDDF appears to be a unique and potent treatment to reduce low-grade chronic inflammation caused by obesity and visceral adiposity. Further studies with more extended follow-up periods are warranted to investigate the long-term anti-inflammatory benefits of DDDF in individuals with increased BMI.

Current status of weight bias and stigma in pediatrics and the need for greater focus on populations at risk

PURPOSE OF REVIEW

Obesity is one of the most common pediatric chronic conditions in the United States, affecting approximately 20% of American youth and is more common amongst Black, Latino, and Indigenous and low socioeconomic populations. The condition places children and adolescents at increased risk of physical and mental health conditions partly mediated by the weight bias and stigmatization experienced during the potentially vulnerable periods of childhood and adolescence.

RECENT FINDINGS

Weight bias and the resulting stigma are pervasive in society. Children have been shown to internalize this bias and its devaluation, which have been shown to contribute to worsening metabolic and mental health outcomes independently. Studies suggest weight stigmatization more adversely affects Black, Latino, and Indigenous children, suggesting the potential for adverse synergistic effects of these historical biases on such youth.

SUMMARY

Addressing childhood obesity successfully across all racial, ethnic, and socioeconomic lines requires addressing weight bias and stigma. Steps toward this end include collaborative efforts to promote cross-cultural competence and upstander bias education and training for those who care for children, person-centered communication, and a culture of inclusivity across governmental, healthcare, educational, entertainment, and advertising sectors.

A Longitudinal Analysis of Weight Changes before and after Total Knee Arthroplasty: Weight Trends, Patterns, and Predictors

Longitudinal data on patient trends in body mass index (BMI) and the proportion that gains or loses significant weight before and after total knee arthroplasty (TKA) are scarce. This study aimed to observe patients longitudinally for a 2-year period and determine (1) clinically significant BMI changes during the 1 year before and 1 year after TKA and (2) identify factors associated with clinically significant weight changes.A prospective cohort of 5,388 patients who underwent primary TKA at a tertiary health care institution between January 2016 and December 2019 was analyzed. The outcome of interests was clinically significant weight changes, defined as a ≥5% change in BMI, during the 1-year preoperative and postoperative periods, respectively. Patient-specific variables and demographics were assessed as potential predictors of weight change using multinomial logistic regression.Overall, 47% had a stable weight throughout the study period (preoperative: 17% gained, 15% lost weight; postoperative: 19% gained, 16% lost weight). Patients who were older (odds ratio [OR] = 0.95), men (OR = 0.47), overweight (OR = 0.36), and Obese Class III (OR = 0.06) were less likely to gain weight preoperatively. Preoperative weight loss was associated with postoperative weight gain 1 year after TKA (OR = 3.03). Preoperative weight gain was associated with postoperative weight loss 1 year after TKA (OR = 3.16).Most patients maintained a stable weight before and after TKA. Weight changes during the 1 year before TKA were strongly associated with reciprocal rebounds in BMI postoperatively, emphasizing the importance of ongoing weight management during TKA and the recognition of patients at higher risk for weight gain.Level of evidence II (prospective cohort study).

Taiwan Association for the Study of the Liver-Taiwan Society of Cardiology Taiwan position statement for the management of metabolic dysfunction- associated fatty liver disease and cardiovascular diseases

Metabolic dysfunction-associated fatty liver disease (MAFLD) is an increasingly common liver disease worldwide. MAFLD is diagnosed based on the presence of steatosis on images, histological findings, or serum marker levels as well as the presence of at least one of the three metabolic features: overweight/obesity, type 2 diabetes mellitus, and metabolic risk factors. MAFLD is not only a liver disease but also a factor contributing to or related to cardiovascular diseases (CVD), which is the major etiology responsible for morbidity and mortality in patients with MAFLD. Hence, understanding the association between MAFLD and CVD, surveillance and risk stratification of MAFLD in patients with CVD, and assessment of the current status of MAFLD management are urgent requirements for both hepatologists and cardiologists. This Taiwan position statement reviews the literature and provides suggestions regarding the epidemiology, etiology, risk factors, risk stratification, nonpharmacological interventions, and potential drug treatments of MAFLD, focusing on its association with CVD.

Branched-chain amino acids prevent obesity by inhibiting the cell cycle in an NADPH-FTO-m6A coordinated manner

Obesity has become a major health crisis in the past decades. Branched-chain amino acids (BCAA), a class of essential amino acids, exerted beneficial health effects with regard to obesity and its related metabolic dysfunction, although the underlying reason is unknown. Here, we show that BCAA supplementation alleviates high-fat diet (HFD)-induced obesity and insulin resistance in mice and inhibits adipogenesis in 3T3-L1 cells. Further, we find that BCAA prevent the mitotic clonal expansion (MCE) of preadipocytes by reducing cyclin A2 (CCNA2) and cyclin-dependent kinase 2 (CDK2) expression. Mechanistically, BCAA decrease the concentration of nicotinamide adenine dinucleotide phosphate (NADPH) in adipose tissue and 3T3-L1 cells by reducing glucose-6-phosphate dehydrogenase (G6PD) expression. The reduced NADPH attenuates the expression of fat mass and obesity-associated (FTO) protein, a well-known m6A demethylase, to increase the N6-methyladenosine (m6A) levels of Ccna2 and Cdk2 mRNA. Meanwhile, the high m6A levels of Ccna2 and Cdk2 mRNA are recognized by YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), which results in mRNA decay and reduction of their protein expressions. Overall, our data demonstrate that BCAA inhibit obesity and adipogenesis by reducing CDK2 and CCNA2 expression via an NADPH-FTO-m6A coordinated manner in vivo and in vitro, which raises a new perspective on the role of m6A in the BCAA regulation of obesity and adipogenesis.

Primary care-led weight-management intervention: qualitative insights into patient experiences at two-year follow-up

PURPOSE

The prevalence of overweight and obesity is continuously increasing globally and long-term weight loss intervention outcomes remain disappointing. To determine which behavioural intervention approaches improve the probability of achieving long-term weight loss, this two-year follow-up study aimed to identify distinct factors and strategies for successful long-term weight loss maintenance.

METHODS

A cohort of 20 participants with overweight and obesity from a primary-care led weight management programme with diverse backgrounds was interviewed at baseline, after 1 and 2 years, and asked to do quantitative self-description. This study focused on the 2-year follow-up interviews from this study series.

RESULTS

We found that agile, continuous self-monitoring with personalized, sustainable lifestyle habits correlated with positive outcomes. Participants reported health benefits, maintained weight loss, and found motivation in supportive peer networks. Challenges like anxiety, disappointment, and disruptions derailed progress. Long-term success relied on a strong support system of healthcare professionals, friends, and family.

CONCLUSIONS

The findings of this study series highlight the intricate nature of long-term weight loss maintenance. This study corroborates the persistence of overarching themes while highlighting the individual variability in their relative importance. Findings emphasize the importance of long-term support to effectively address the diverse needs of patients trying to achieve long-term weight loss maintenance.

Primary care-led weight-management intervention: qualitative insights into patient experiences at one-year follow up

INTRODUCTION

The global prevalence of overweight and obesity is continuously increasing. Long-term weight loss results remain disappointing. This study aims to identify factors and strategies for successful long-term weight loss in a primary care-led weight-loss intervention from the perspective of participants.

MATERIALS AND METHODS

This qualitative interview study is the first follow-up study in a 2-year study series of participants with overweight or obesity. Methods utilized are semi-structured interviews (n = 20) with quantitative self-description. The data were transcribed from audio-taped interviews and analysed thematically.

RESULTS

This study found that clear, continuously evolving self-monitoring strategies facilitated by strong routines and a long-term focus enhanced successful outcomes. Challenges faced included stress, disappointment and loss of routine along with external criticism and discouragement. Benefits experienced due to weight loss included improved health, self-esteem, communal support and encouragement, which continued to fuel motivation. Receiving continuous support and encouragement from healthcare practitioners was instrumental for long-term success.

CONCLUSION

This study highlighted the complex, multifaceted experiences patients encounter in the pursuit of trying to achieve long-term weight loss. Personalized treatment protocols taking into account the diverse requirements and circumstances of individuals have the potential to improve treatment outcomes. Continuous, professional support may enhance long-term outcomes.

New insights in the mechanisms of weight-loss maintenance: Summary from a Pennington symposium

Obesity is a chronic disease that affects more than 650 million adults worldwide. Obesity not only is a significant health concern on its own, but predisposes to cardiometabolic comorbidities, including coronary heart disease, dyslipidemia, hypertension, type 2 diabetes, and some cancers. Lifestyle interventions effectively promote weight loss of 5% to 10%, and pharmacological and surgical interventions even more, with some novel approved drugs inducing up to an average of 25% weight loss. Yet, maintaining weight loss over the long-term remains extremely challenging, and subsequent weight gain is typical. The mechanisms underlying weight regain remain to be fully elucidated. The purpose of this Pennington Biomedical Scientific Symposium was to review and highlight the complex interplay between the physiological, behavioral, and environmental systems controlling energy intake and expenditure. Each of these contributions were further discussed in the context of weight-loss maintenance, and systems-level viewpoints were highlighted to interpret gaps in current approaches. The invited speakers built upon the science of obesity and weight loss to collectively propose future research directions that will aid in revealing the complicated mechanisms involved in the weight-reduced state.

Effects of Diet Macronutrient Composition on Weight Loss during Caloric Restriction and Subsequent Weight Regain during Refeeding in Aging Mice

Caloric restriction (CR) induces weight loss, but is associated with rapid weight regain upon return to ad libitum feeding. Our aim was to investigate effects of the macronutrient composition of the diet on weight loss and regain in elderly mice. Males, 18 months old, of the C57BL/6J strain were subjected to 4-week 30% CR followed by 4 weeks of ad libitum refeeding on either high-carb (HC), high-fat (HF) or high-protein (HP) diets (n = 22 each). Mice (n = 11) fed a chow diet ad libitum served as a control group (CON). Body mass and food intake were monitored daily. Twenty-four-hour indirect calorimetry was used to assess energy expenditure and substrate oxidation. Muscle and fat mass were evaluated with dissection of the tissues. Serum leptin and ghrelin levels were also measured. CR-induced weight loss did not differ between the diets. Weight regain was particularly fast for HF as mice overshot their initial weight by 12.8 ± 5.7% after 4-week refeeding when HC and HP mice reached the weight of the CON group. Weight regain strongly correlated with energy intake across the groups. The respiratory exchange ratio was lower in HF mice (0.81 ± 0.03) compared to HC (0.94 ± 0.06, p < 0.001), HP (0.89 ± 0.04, p < 0.001) and CON mice (0.91 ± 0.06, p < 0.01) during the refeeding. Serum leptin levels were higher in HF mice (1.03 ± 0.50 ng/mL) compared to HC (0.46 ± 0.14, p < 0.001), HP (0.63 ± 0.28, p < 0.05) or CON mice (0.41 ± 0.14, p < 0.001). Thus, CR induces similar weight loss in aging mice irrespective of the diet's macronutrient composition. An HF diet leads to excessive energy intake and pronounced gain in body fat in spite of increased fat oxidation and serum leptin during the refeeding after CR.

Studies on the fat mass and obesity-associated (FTO) gene and its impact on obesity-associated diseases

Obesity has become a major health crisis in the past ∼50 years. The fat mass and obesity-associated (FTO) gene, identified by genome-wide association studies (GWAS), was first reported to be positively associated with obesity in humans. Mice with more copies of the FTO gene were observed to be obese, while loss of the gene in mice was found to protect from obesity. Later, FTO was found to encode an m6A RNA demethylase and has a profound effect on many biological and metabolic processes. In this review, we first summarize recent studies that demonstrate the critical roles and regulatory mechanisms of FTO in obesity and metabolic disease. Second, we discuss the ongoing debates concerning the association between FTO polymorphisms and obesity. Third, since several small molecule drugs and micronutrients have been found to regulate metabolic homeostasis through controlling the expression or activity of FTO, we highlight the broad potential of targeting FTO for obesity treatment. Improving our understanding of FTO and the underlying mechanisms may provide new approaches for treating obesity and metabolic diseases.

The inverted U-shaped relationship between weight loss percentage and cardiovascular health scores

PURPOSE

Obesity is a significant risk factor for cardiovascular disease; however, the impact of weight loss on cardiovascular health (CVH) in individuals with specific obesity patterns remains incompletely understood. The objective of our study was to investigate the relationship weight loss percentage and CVH scores across individuals with various obesity patterns.

METHODS

Our study utilized data from the National Health and Nutrition Examination Survey conducted between 2007 and 2018, involving a total of 12,835 participants aged 16 years or older, to conduct a cross-sectional analysis. Multiple linear regression and multinomial logistic regression methods were used to assess the correlation between the weight loss percentage and the CVH scores. Additionally, restricted cubic spline analysis was employed to examine the nonlinear relationship between the two variables.

RESULTS

Compared to individuals with a weight loss percentage < 0%, participants with weight loss percentages of 0-5% and 5.1-10% showed improved CVH scores, with β values of 2.85 (95% CI 2.32-3.38) and 2.55 (95% CI 1.69-3.4), respectively. Regarding different obesity patterns, compared to participants with a weight loss percentage < 0%, participants with a weight loss percentage of 0-5% showed an increase in CVH scores in the normal weight and overweight/general obesity (OGO) groups, with β values of 1.45 (95% CI 0.7-2.19) and 1.22 (95% CI 0.46-1.97), respectively. Restricted cubic spline analysis revealed a significant inverted U-shaped relationship between the weight loss percentage and the CVH scores (with optimal CVH scores at 3%).

CONCLUSIONS

There was an inverted U-shaped relationship between weight loss percentage and CVH scores, with moderate weight loss (0-10%, optimal value of 3%) being associated with improved CVH scores, especially among individuals with OGO.

LEVEL V

Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Models of body weight and fatness regulation

Body weight and fatness appear to be regulated phenomena. Several different theoretical models are available to capture the essence of this idea. These include the set-point, dynamic equilibrium, adiposity force, control theory-settling point, Hall-Guo, operation point and dual intervention point (DIP) models. The set-point model posits a single reference point around which levels of fat are regulated. The dynamic equilibrium model suggests that the apparent regulation of body fat around a reference point is an illusion owing to the necessary impacts of weight change on energy expenditure. Control theory focuses on the importance of feedback gain and suggests set-point and dynamic equilibrium are ends of a continuum of feedback gain. Control theory models have also been called 'settling point' models. The Hall-Guo, operation point and DIP models also bring together the set-point and dynamic equilibrium ideas into a single framework. The DIP proposes a zone of indifference where dynamic equilibrium 'regulation' predominates, bounded by upper and lower intervention points beyond which physiological mechanisms are activated. The drifty gene hypothesis is an idea explaining where this individual variation in the upper intervention point might come from. We conclude that further experiments to test between the models are sorely required. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Carbohydrate-insulin model: does the conventional view of obesity reverse cause and effect?

Conventional obesity treatment, based on the First Law of Thermodynamics, assumes that excess body fat gain is driven by overeating, and that all calories are metabolically alike in this regard. Hence, to lose weight one must ultimately eat less and move more. However, this prescription rarely succeeds over the long term, in part because calorie restriction elicits predictable biological responses that oppose ongoing weight loss. The carbohydrate-insulin model posits the opposite causal direction: overeating doesn't drive body fat increase; instead, the process of storing excess fat drives overeating. A diet high in rapidly digestible carbohydrates raises the insulin-to-glucagon ratio, shifting energy partitioning towards storage in adipose, leaving fewer calories for metabolically active and fuel sensing tissues. Consequently, hunger increases, and metabolic rate slows in the body's attempt to conserve energy. A small shift in substrate partitioning though this mechanism could account for the slow but progressive weight gain characteristic of common forms of obesity. From this perspective, the conventional calorie-restricted, low-fat diet amounts to symptomatic treatment, failing to target the underlying predisposition towards excess fat deposition. A dietary strategy to lower insulin secretion may increase the effectiveness of long-term weight management and chronic disease prevention. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Validity of Actigraph for Measuring Energy Expenditure in Healthy Adults: A Systematic Review and Meta-Analysis

PURPOSE

The objective of this systematic review and meta-analysis was to assess the validity of the Actigraph triaxial accelerometer device in measuring physical activity energy expenditure (PAEE) in healthy adults, with indirect calorimetry (IC) serving as the validity criterion.

METHODS

A comprehensive search was conducted using the PubMed, Web of Science, and sportdiscuss databases, in addition to manual searches for supplementary sources. Search strategies were employed that involved conducting single keyword searches using the terms "gt3x" and "Actigraph gt3x". The literature search encompassed the timeframe spanning from 1 January 2010 to 1 March 2023. The methodological quality of the studies included in the analysis was evaluated using both the Downs and Black checklist and the Consensus-Based Criteria for Selection of Measurement Instruments (COSMIN) checklist. The meta-analysis was conducted using the Review Manager 5.4 software. The standardized mean difference (SMD) was calculated and expressed as a 95% confidence interval (CI). The significance level was set at α = 0.05. A systematic assessment of the Actigraph's performance was conducted through the descriptive analysis of computed effect sizes.

RESULTS

A total of 4738 articles were retrieved from the initial search. After eliminating duplicate articles and excluding those deemed irrelevant, a comprehensive analysis was conducted on a total of 20 studies, encompassing a combined sample size of 1247 participants. The scores on the Downs and Black checklist ranged from 10 to 14, with a mean score of 11.35. The scores on the COSMIN checklist varied from 50% to 100%, with an average score of 65.83%. The meta-analysis findings revealed a small effect size (SMD = 0.01, 95% CI = 0.50-0.52, p = 0.97), indicating no statistically significant difference (p > 0.05).

CONCLUSIONS

The meta-analysis revealed a small effect size when comparing the Actigraph and IC, suggesting that the Actigraph can be utilized for assessing total PAEE. Descriptive analyses have indicated that the Actigraph device has limited validity in accurately measuring energy expenditure during specific physical activities, such as high-intensity and low-intensity activities. Therefore, caution should be exercised when utilizing this device for such purposes. Furthermore, there was a significant correlation between the activity counts measured by the Actigraph and the PAEE, indicating that activity counts can be utilized as a predictive variable for PAEE.

Sweetness preference and its impact on energy intake and body weight - a review of evidence

In the last few years, several approaches have been postulated for tackling the global increase in overweight and obesity rates, including different dietary macronutrient compositions or the timing of meals. Recently, taste modulation has come into focus as a possible approach for influencing dietary behavior. The perception of sweet taste is innate and an evolutionary protection mechanism to prevent primates from eating poisonous plants. It is hypothesized that this innate sweetness preference could be modulated by dietary sweetness, including sweet foods and beverages, which results in a learned sweetness preference that affects energy intake and body weight. However, this hypothesis is not supported by unanimous scientific evidence. This review provides an update of the current literature, regarding the modulation of sweetness preference as a possible new approach in the prevention of overweight and obesity. In general, results from observation as well as interventional studies in all age groups are heterogeneous. The majority showed no effect of dietary sweetness modulation on sweetness preference, energy intake or anthropometric measures. Therefore, the modulation of sweetness preference due to diet, foods or beverages is still a hypothesis and not scientifically proven. However, due to the lack of data, more research is necessary.

Effects of ketone bodies on energy expenditure, substrate utilization, and energy intake in humans

The potential of ketogenic approaches to regulate energy balance has recently gained attention since ketones may influence both energy expenditure and energy intake. In this narrative review, we summarized the most relevant evidence about the role of ketosis on energy expenditure, substrate utilization, and energy intake in humans. We considered different strategies to induce ketosis, such as fasting, dietary manipulation, and exogenous ketone sources. In general, ketosis does not have a major influence on energy expenditure but promotes a shift in substrate utilization towards ketone body oxidation. The strategies to induce ketosis by reduction of dietary carbohydrate availability (e.g., ketogenic diets) do not independently influence energy intake, being thus equally effective for weight loss as diets with higher carbohydrate content. In contrast, the intake of medium-chain triglycerides and ketone esters induces ketosis and appears to increase energy expenditure and reduce energy intake in the context of high carbohydrate availability. These latter strategies lead to slightly enhanced weight loss. Unfortunately, distinguishing the effects of the various ketogenic strategies per se from the effects of other physiological responses is not possible with the available human data. Highly controlled, inpatient studies using targeted strategies to isolate the independent effects of ketones are required to adequately address this knowledge gap.

High Prevalence of Energy and Nutrients Inadequacy among Brazilian Older Adults

Poor nutrition increases the risk of diseases and adverse health outcomes in older adults. We evaluated the potential inadequacy of nutrient intake among older adults in Brazil and its association with body anthropometry and composition outcomes. Dietary intake was obtained from 295 community-living older adults (>60 years old), of both genders, using a seven-day food record. Nutrient inadequacy was further identified based on the Dietary Reference Intakes and European Guidelines. Skeletal muscle mass (SM), strength and performance, and the diagnosis of sarcopenia were assessed using reference methods. Nutritional inadequacy was high, with energy, dietary fiber, and six micronutrients exhibiting the greatest inadequacy levels (>80%). Energy intake was correlated with SM strength (p = 0.000) and performance (p = 0.001). Inadequate energy, fiber, and protein intakes influenced BMI, while inadequate intake of vitamin B6 directly affected the diagnosis of sarcopenia (p ≤ 0.005). Further research is required to investigate whether these inadequacies can be associated with other clinical health outcomes.

Factors that predict weight loss success differ by diet intervention type

Background

Many types of diet intervention can achieve negative energy balance and successful weight loss in persons with obesity. However, within any dietary strategy, there is large inter-individual variation in the weight loss response. The aim of this study is to determine factors that predict weight loss success for diet interventions that vary by macronutrient and caloric composition.

Methods

Participants with BMI 30.0 to 49.9 kg/m2 self-selected one of three diet intervention trials for weight loss: low carbohydrate (LOW CHO), low fat (LOW FAT), or low calorie (LOW KCAL). Multivariable regression models were developed to determine the significance of predictor demographic, body composition, metabolic, clinical, and dietary variables for each diet type.

Results

Weight loss over 12-16 weeks averaging -5.1 ± 4.0 kg from baseline weight, p < 0.001, was not significantly different among diet types. Several different factors were identified that account for the inter-individual variance in weight loss success. Regardless of diet type, the most robust predictor of weight loss success was completion of the intervention, accounting for 20-30% of the variance. Factors predicting diet intervention completion were age, physical activity level, blood leptin level, blood pressure, and the amount of weight loss occurring. Differences by diet type in cardiometabolic risk factor reduction were identified with LOW CHO decreasing glycemia/insulinemia factors, LOW FAT decreasing lipidemia factors, and LOW KCAL decreasing inflammatory factors.

Conclusion

These data provide evidence to inform more precise and personalized approaches to diet intervention for weight loss and cardiometabolic health.

GDF15 promotes weight loss by enhancing energy expenditure in muscle

Caloric restriction that promotes weight loss is an effective strategy for treating non-alcoholic fatty liver disease and improving insulin sensitivity in people with type 2 diabetes1. Despite its effectiveness, in most individuals, weight loss is usually not maintained partly due to physiological adaptations that suppress energy expenditure, a process known as adaptive thermogenesis, the mechanistic underpinnings of which are unclear2,3. Treatment of rodents fed a high-fat diet with recombinant growth differentiating factor 15 (GDF15) reduces obesity and improves glycaemic control through glial-cell-derived neurotrophic factor family receptor α-like (GFRAL)-dependent suppression of food intake4-7. Here we find that, in addition to suppressing appetite, GDF15 counteracts compensatory reductions in energy expenditure, eliciting greater weight loss and reductions in non-alcoholic fatty liver disease (NAFLD) compared to caloric restriction alone. This effect of GDF15 to maintain energy expenditure during calorie restriction requires a GFRAL-β-adrenergic-dependent signalling axis that increases fatty acid oxidation and calcium futile cycling in the skeletal muscle of mice. These data indicate that therapeutic targeting of the GDF15-GFRAL pathway may be useful for maintaining energy expenditure in skeletal muscle during caloric restriction.

The Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD), Aas AM, Axelsen M, Churuangsuk C, Hermansen K, Kendall CWC, Kahleova H, Khan T, Lean MEJ, Mann JI, Pedersen E, Pfeiffer A, Rahelić D, Reynolds AN, Risérus U, Rivellese AA, Salas-Salvadó J, Schwab U, Sievenpiper JL, Thanopoulou A, Uusitupa EM. Evidence-based European recommendations for the dietary management of diabetes

Diabetes management relies on effective evidence-based advice that informs and empowers individuals to manage their health. Alongside other cornerstones of diabetes management, dietary advice has the potential to improve glycaemic levels, reduce risk of diabetes complications and improve health-related quality of life. We have updated the 2004 recommendations for the nutritional management of diabetes to provide health professionals with evidence-based guidelines to inform discussions with patients on diabetes management, including type 2 diabetes prevention and remission. To provide this update we commissioned new systematic reviews and meta-analyses on key topics, and drew on the broader evidence available. We have strengthened and expanded on the previous recommendations to include advice relating to dietary patterns, environmental sustainability, food processing, patient support and remission of type 2 diabetes. We have used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach to determine the certainty of evidence for each recommendation based on findings from the commissioned and identified systematic reviews. Our findings indicate that a range of foods and dietary patterns are suitable for diabetes management, with key recommendations for people with diabetes being largely similar for those for the general population. Important messages are to consume minimally processed plant foods, such as whole grains, vegetables, whole fruit, legumes, nuts, seeds and non-hydrogenated non-tropical vegetable oils, while minimising the consumption of red and processed meats, sodium, sugar-sweetened beverages and refined grains. The updated recommendations reflect the current evidence base and, if adhered to, will improve patient outcomes.