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

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.

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.

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.

Impact of Body Composition on Sleep and Its Relationship with Sleep Disorders: Current Insights

Sleep is involved in many physiological processes and is essential for both physical and mental health. Obesity and sleep deprivation due to sleep disorders are major public health issues. Their incidence is increasing, and they have a wide range of adverse health-related consequences, including life-threatening cardiovascular disease. The impact of sleep on obesity and body composition is well-known, and many studies have shown an association between insufficient or excessive sleep duration and obesity, body fat percentage, and weight gain. However, there is growing evidence of the effects of body composition on sleep and sleep disorders (particularly sleep disordered breathing) through anatomical and physiological mechanisms (nocturnal fluid shift, core body temperature, or diet). Although some research has been conducted on the bidirectional effects of sleep-disordered breathing and body composition, the specific effects of obesity and body composition on sleep and the underlying mechanisms that explain these effects remain unclear. Therefore, this review summarizes the findings on the effects of body composition on sleep and draws conclusions and proposals for future research in this field.

Association of Macronutrients Intake with Body Composition and Sarcopenic Obesity in Children and Adolescents: A Population-Based Analysis of the National Health and Nutrition Examination Survey (NHANES) 2011-2018

The association of macronutrients intake with body composition and sarcopenic obesity remains uncertain in children and adolescents. We aimed to explore the association between macronutrients intake and body composition, especially sarcopenic obesity, in children and adolescents residing in the United States. The study utilized data from 5412 participants aged 6-17 years who attended NHANES between 2011 and 2018. Body composition was assessed using DXA, and nutrient intake was based on 24-h recall. Multivariable linear regression and multinomial logistic regression were used. The unweighted prevalence of sarcopenic obesity was 15.6%. A higher percentage of energy (5 %E) from fat was inversely associated with muscle mass but positively associated with fat mass and sarcopenic obesity. Substituting carbohydrate (5 %E) with fat decreased muscle mass by 0.03 (95% CI 0.01 to 0.06) but increased fat mass by 0.03 (95% CI 0.01 to 0.06) and increased the prevalence of sarcopenic obesity by 254% (95% CI 15% to 487%). Replacing protein intake with fat intake also increased the OR of sarcopenic obesity (OR, 2.36 [95% CI 1.18 to 3.18]). In conclusion, a high-fat diet, coupled with low carbohydrate/protein intake, is associated with sarcopenic obesity among children and adolescents. The change in children's diet towards a healthy diet with low fat composition may help prevent sarcopenic obesity. However, randomized clinical trials or longitudinal studies are needed to further validate our findings.

Is Type 2 Diabetes Mellitus a Behavioural Disorder? An Evidence Review for Type 2 Diabetes Mellitus Prevention and Remission through Lifestyle Modification

The prevalence of type 2 diabetes mellitus (T2DM) is steadily rising worldwide due to an increasingly sedentary lifestyle combined with unhealthy food habits. Currently, the burden of diabetes on healthcare systems is unprecedented and rising daily. Several observational studies and randomized controlled trials provide clinical evidence that T2DM remission is possible by adopting dietary interventions and a strict exercise training protocol. Notably, these studies provide ample evidence for remission in patients with T2DM or for prevention in those with risk factors for the disease through various non-pharmacological behavioural interventions. In this article, we present two clinical cases of individuals who showed remission from T2DM/prediabetes via behavioural changes, especially through the adoption of a low-energy diet and exercise. We also discuss the recent advances in T2DM and obesity research, focusing on nutritional interventions and exercise and their benefits for weight loss, improved metabolic profile, enhanced glycaemic control and remission of diabetes.

Gut microbiota-bile acids-glucagon like peptide-1 axis contributes the resistance to high fat diet-induced obesity in mice

In human and rodents, some individuals may remain lean even when they are challenged with high calorie intake. The underlying mechanism for resistance to diet-induced obesity was poorly understood. Here, we used C57BL/6J mice to establish animal models of high-fat diet (HFD) induced obesity sensitive (DIO) mice and obesity resistant (DIR) mice. We then investigated the role of gut microbiota, bile acids (BAs) and brown adipose tissue (BAT) thermogenesis in the development of DIR. Reduced fat accumulation, increased glucose tolerance and energy expenditure through BAT activation were observed in DIR mice. The plasma BAs of DIR mice especially the unconjugated BAs were significantly decreased, while intestine tauro-conjugated bile acids (T-CA, T-β-MCA, T-ω-MCA and T-UDCA) were significantly increased in DIR mice. The composition of the gut flora also changed drastically, and negative correlation was found between metabolic profiles (plasma TG, TC, LDL and body weight) and the abundance of Ruminiclostridium in DIR mice, while genus Anaerotruncus abundance in DOR mice was found to be positively correlated. After fecal microbiota transplants, HFD fed recipient mice exhibited a trend toward reduced adiposity and improved glucose tolerance, while showing increased serum tauro-conjugated BAs levels. STC-1 cell experiments confirmed tauro-conjugated BA (T-β-MCA) activated FXR/TGR5 pathway and induced the production of GLP-1, inhibiting genes that regulate the ceramide synthesis. Our results indicated that the DIR mice exhibited higher energy expenditure by activating BAT thermogenesis, which may be related altered gut microbiota-bile acids-glucagon like peptide-1 axis.

Effect and mechanism of Magnolia officinalis pharmacopuncture for treating localized fat via network pharmacology and experimental study

Background

Recently, for various reasons, the need for non-invasive treatment for localized fat has emerged. This study confirmed whether Magnolia officinalis (MO) pharmacopuncture reduces localized fat by promoting lipolysis and inhibiting adipogenesis.

Methods

The network was built using genes related to the active compound of MO and the mode of action of MO was predicted by the functional enrichment analysis. Based on the result from network analysis, 100 µL of 2 mg/mL MO pharmacopuncture was injected into the inguinal fat pad for 6 weeks in obese C57BL/6J mice. Normal saline was injected into the right-side inguinal fat pad as a self-control.

Results

It was expected that the 'AMP-activated protein kinase (AMPK) signaling pathway' would be affected by the MO Network. MO pharmacopuncture reduced the weight and size of inguinal fat in HFD-induced obese mice. The phosphorylation of AMPK along with the increases of lipases was significantly increased by MO injection. Also, the expression levels of fatty acid synthesize-related mediators were suppressed by MO injection.

Conclusion

Our results demonstrated that MO pharmacopuncture promoted the expression of AMPK, which has beneficial effects on activation of lipolysis and inhibition of lipogenesis. Pharmacopuncture of MO can be a non-surgical alternative therapy in the treatment of local fat tissue.

Citral Modulates MMP-2 and MMP-9 Activities on Healing of Gastric Ulcers Associated with High-Fat Diet-Induced Obesity

Obesity causes low-grade inflammation that results in the development of comorbidities. In people with obesity, exacerbation of gastric lesion severity and delayed healing may aggravate gastric mucosal lesions. Accordingly, we aimed to evaluate the citral effects on gastric lesion healing in eutrophic and obese animals. C57Bl/6 male mice were divided into two groups: animals fed a standard diet (SD) or high-fat diet (HFD) for 12 weeks. Gastric ulcers were induced using acetic acid (80%) in both groups. Citral (25, 100, or 300 mg/kg) was administered orally for 3 or 10 days. A vehicle-treated negative control (1% Tween 80, 10 mL/kg) and lansoprazole-treated (30 mg/kg) were also established. Lesions were macroscopically examined by quantifying regenerated tissue and ulcer areas. Matrix metalloproteinases (MMP-2 and -9) were analyzed by zymography. The ulcer base area between the two examined periods was significantly reduced in HFD 100 and 300 mg/kg citral-treated animals. In the 100 mg/kg citral-treated group, healing progression was accompanied by reduced MMP-9 activity. Accordingly, HFD could alter MMP-9 activity, delaying the initial healing phase. Although macroscopic changes were undetectable, 10-day treatment with 100 mg/kg citral exhibited improved scar tissue progression in obese animals, with reduced MMP-9 activity and modulation of MMP-2 activation.

Restricting sugar or carbohydrate intake does not impact physical activity level or energy intake over 24 h despite changes in substrate use: a randomised crossover study in healthy men and women

PURPOSE

To determine the effects of dietary sugar or carbohydrate restriction on physical activity energy expenditure, energy intake, and physiological outcomes across 24 h.

METHODS

In a randomized, open-label crossover design, twenty-five healthy men (n = 10) and women (n = 15) consumed three diets over a 24-h period: moderate carbohydrate and sugar content (MODSUG = 50% carbohydrate [20% sugars], 15% protein, 35% fat); low sugar content (LOWSUG = 50% carbohydrate [< 5% sugars], 15% protein, 35% fat); and low carbohydrate content (LOWCHO = 8% carbohydrate [< 5% sugars], 15% protein, 77% fat). Postprandial metabolic responses to a prescribed breakfast (20% EI) were monitored under laboratory conditions before an ad libitum test lunch, with subsequent diet and physical activity monitoring under free-living conditions until blood sample collection the following morning.

RESULTS

The MODSUG, LOWSUG and LOWCHO diets resulted in similar mean [95%CI] rates of both physical activity energy expenditure (771 [624, 919] vs. 677 [565, 789] vs. 802 [614, 991] kcal·d-1; p = 0.29] and energy intake (2071 [1794, 2347] vs. 2195 [1918, 2473] vs. 2194 [1890, 2498] kcal·d-1; P = 0.34), respectively. The LOWCHO condition elicited the lowest glycaemic and insulinaemic responses to breakfast (P < 0.01) but the highest 24-h increase in LDL-cholesterol concentrations (P < 0.001), with no differences between the MODSUG and LOWSUG treatments. Leptin concentrations decreased over 24-h of consuming LOWCHO relative to LOWSUG (p < 0.01).

CONCLUSION

When energy density is controlled for, restricting either sugar or total dietary carbohydrate does not modulate physical activity level or energy intake over a 24-h period (~ 19-h free-living) despite substantial metabolic changes.

CLINICAL TRIALS REGISTRATION ID

NCT03509610, https://clinicaltrials.gov/show/NCT03509610.

High sucrose consumption decouples intrinsic and synaptic excitability of AgRP neurons without altering body weight

BACKGROUND/OBJECTIVE

As the obesity epidemic continues, the understanding of macronutrient influence on central nervous system function is critical for understanding diet-induced obesity and potential therapeutics, particularly in light of the increased sugar content in processed foods. Previous research showed mixed effects of sucrose feeding on body weight gain but has yet to reveal insight into the impact of sucrose on hypothalamic functioning. Here, we explore the impact of liquid sucrose feeding for 12 weeks on body weight, body composition, caloric intake, and hypothalamic AgRP neuronal function and synaptic plasticity.

METHODS

Patch-clamp electrophysiology of hypothalamic AgRP neurons, metabolic phenotyping and food intake were performed on C57BL/6J mice.

RESULTS

While mice given sugar-sweetened water do not gain significant weight, they do show subtle differences in body composition and caloric intake. When given sugar-sweetened water, mice show similar alterations to AgRP neuronal excitability as in high-fat diet obese models. Increased sugar consumption also primes mice for increased caloric intake and weight gain when given access to a HFD.

CONCLUSIONS

Our results show that elevated sucrose consumption increased activity of AgRP neurons and altered synaptic excitability. This may contribute to obesity in mice and humans with access to more palatable (HFD) diets.

Obesity among Latinx people in the United States: A review

Obesity is a serious, chronic disease that is associated with a range of adiposity-based comorbidities, including cardiovascular disease, type 2 diabetes, and nonalcoholic fatty liver disease. In the United States, obesity is a public health crisis, affecting more than 40% of the population. Obesity disproportionately affects Latinx people, who have a higher prevalence of obesity and related comorbidities (such as cardiovascular disease, type 2 diabetes, and nonalcoholic fatty liver disease) compared with the general population. Many factors, including genetic predisposition, environmental factors, traditional calorie-dense Latinx diets, family dynamics, and differences in socioeconomic status, contribute to the increased prevalence and complexity of treating obesity in the Latinx population. Additionally, significant heterogeneity within the Latinx population and disparities in health care access and utilization between Latinx people and the general population add to the challenge of obesity management. Culturally tailored interventions have been successful for managing obesity and related comorbidities in Latinx people. Antiobesity medications and bariatric surgery are also important options for obesity treatment in Latinx people. As highlighted in this review, when managing obesity in the Latinx population, it is critical to consider the impact of genetic, dietary, cultural, and socioeconomic factors, in order to implement an individualized treatment strategy.

Eating, diet, and nutrition for the treatment of non-alcoholic fatty liver disease

Nutrition and dietary interventions are a central component in the pathophysiology, but also a cornerstone in the management of patients with non-alcoholic fatty liver disease (NAFLD). Summarizing our rapidly advancing understanding of how our diet influences our metabolism and focusing on specific effects on the liver, we provide a comprehensive overview of dietary concepts to counteract the increasing burden of NAFLD. Specifically, we emphasize the importance of dietary calorie restriction independently of the macronutrient composition together with adherence to a Mediterranean diet low in added fructose and processed meat that seems to exert favorable effects beyond calorie restriction. Also, we discuss intermittent fasting as a type of diet specifically tailored to decrease liver fat content and increase ketogenesis, awaiting future study results in NAFLD. Finally, personalized dietary recommendations could be powerful tools to increase the effectiveness of dietary interventions in patients with NAFLD considering the genetic background and the microbiome, among others.

Maternal high-fat diet consumption during pregnancy and lactation predisposes offspring to renal and metabolic injury later in life: comparative study of diets with different lipid contents

Accumulating evidence suggests that maternal overnutrition can result in a higher development risk of obesity and renal disease in the offspring's adulthood. The present study tested different lipid levels in the maternal diet during pregnancy and lactation and its repercussions on the offspring of Wistar rats. Offspring of 1, 7, 30 and 90-d-old were divided into the following groups: Control (CNT) - offspring of dams that consumed a standard chow diet (3.5% of lipids); Experimental 1 (EXP1) - offspring of dams exposed to a high-fat diet (HFD) (28% of lipids); and Experimental 2 (EXP2) - offspring of dams exposed to a HFD (40% of lipids). Regarding maternal data, there was a decrease in the amount of diet ingested by EXP2. Daily caloric intake was higher in EXP1, while protein and carbohydrate intakes were lower in EXP2. While lipid intake was higher in the experimental groups, EXP1 consumed more lipids than EXP2, despite the body weight gain being higher in EXP2. Adult offspring from EXP1 presented higher blood glucose. Regarding morphometric analysis, in both experimental groups, there was an increase in the glomerular tuft and renal corpuscle areas, but an increase in the capsular space area only in EXP1. There was a decrease in the glomerular filtration rate (GFR) in EXP1, in contrast to an increase in GFR of EXP2, along with an increase in urinary protein excretion. In conclusion, the maternal HFDs caused significant kidney damage in offspring, but had different repercussions on the type and magnitude of recorded change.

Regulation of body weight: Lessons learned from bariatric surgery

BACKGROUND

Bariatric or weight loss surgery is currently the most effective treatment for obesity and metabolic disease. Unlike dieting and pharmacology, its beneficial effects are sustained over decades in most patients, and mortality is among the lowest for major surgery. Because there are not nearly enough surgeons to implement bariatric surgery on a global scale, intensive research efforts have begun to identify its mechanisms of action on a molecular level in order to replace surgery with targeted behavioral or pharmacological treatments. To date, however, there is no consensus as to the critical mechanisms involved.

SCOPE OF REVIEW

The purpose of this non-systematic review is to evaluate the existing evidence for specific molecular and inter-organ signaling pathways that play major roles in bariatric surgery-induced weight loss and metabolic benefits, with a focus on Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), in both humans and rodents.

MAJOR CONCLUSIONS

Gut-brain communication and its brain targets of food intake control and energy balance regulation are complex and redundant. Although the relatively young science of bariatric surgery has generated a number of hypotheses, no clear and unique mechanism has yet emerged. It seems increasingly likely that the broad physiological and behavioral effects produced by bariatric surgery do not involve a single mechanism, but rather multiple signaling pathways. Besides a need to improve and better validate surgeries in animals, advanced techniques, including inducible, tissue-specific knockout models, and the use of humanized physiological traits will be necessary. State-of-the-art genetically-guided neural identification techniques should be used to more selectively manipulate function-specific pathways.

Machine-learning prediction of BMI change among doctors and nurses in North China during the COVID-19 pandemic

Objective

The COVID-19 pandemic has become a major public health concern over the past 3 years, leading to adverse effects on front-line healthcare workers. This study aimed to develop a Body Mass Index (BMI) change prediction model among doctors and nurses in North China during the COVID-19 pandemic, and further identified the predicting effects of lifestyles, sleep quality, work-related conditions, and personality traits on BMI change.

Methods

The present study was a cross-sectional study conducted in North China, during May-August 2022. A total of 5,400 doctors and nurses were randomly recruited from 39 COVID-19 designated hospitals and 5,271 participants provided valid responses. Participants' data related to social-demographics, dietary behavior, lifestyle, sleep, personality, and work-related conflicts were collected with questionnaires. Deep Neural Network (DNN) was applied to develop a BMI change prediction model among doctors and nurses during the COVID-19 pandemic.

Results

Of participants, only 2,216 (42.0%) individuals kept a stable BMI. Results showed that personality traits, dietary behaviors, lifestyles, sleep quality, burnout, and work-related conditions had effects on the BMI change among doctors and nurses. The prediction model for BMI change was developed with a 33-26-20-1 network framework. The DNN model achieved high prediction efficacy, and values of R ², MAE, MSE, and RMSE for the model were 0.940, 0.027, 0.002, and 0.038, respectively. Among doctors and nurses, the top five predictors in the BMI change prediction model were unbalanced nutritional diet, poor sleep quality, work-family conflict, lack of exercise, and soft drinks consumption.

Conclusion

During the COVID-19 pandemic, BMI change was highly prevalent among doctors and nurses in North China. Machine learning models can provide an automated identification mechanism for the prediction of BMI change. Personality traits, dietary behaviors, lifestyles, sleep quality, burnout, and work-related conditions have contributed to the BMI change prediction. Integrated treatment measures should be taken in the management of weight and BMI by policymakers, hospital administrators, and healthcare workers.

Experimental diets dictate the metabolic benefits of probiotics in obesity

Growing evidence supports the use of probiotics to prevent or mitigate obesity-related dysmetabolism and non-alcoholic fatty liver disease (NAFLD). However, frequent reports of responders versus non-responders to probiotic treatment warrant a better understanding of key modifiers of host-microbe interactions. The influence of host diet on probiotic efficacy, in particular against metabolic diseases, remains elusive. We fed C57BL6/J mice a low fat reference diet or one of two energy-matched high fat and high sucrose diets for 12 weeks; a classical high fat diet (HFD) and a customized fast food-mimicking diet (FFMD). During the studies, mice fed either obesogenic diet were gavaged daily with one of two probiotic lactic acid bacteria (LAB) strains previously classified as Lactobaccillus, namely Limosilactobacillus reuteri (L. reuteri)or Lacticaseibacillus paracaseisubsp. paracasei (L. paracasei), or vehicle. The tested probiotics exhibited a reproducible efficacy but dichotomous response according to the obesogenic diets used. Indeed, L. paracaseiprevented weight gain, improved insulin sensitivity, and protected against NAFLD development in mice fed HFD, but not FFMD. Conversely, L. reuteri improved glucoregulatory capacity, reduced NAFLD development, and increased distal gut bile acid levels associated with changes in predicted functions of the gut microbiota exclusively in the context of FFMD-feeding. We found that the probiotic efficacy of two LAB strains is highly dependent on experimental obesogenic diets. These findings highlight the need to carefully consider the confounding impact of diet in order to improve both the reproducibility of preclinical probiotic studies and their clinical research translatability.

Enhanced sweet taste perception in obesity: Joint analysis of gustatory data from multiple studies

Introduction

While sweet taste perception is a potential determinant of feeding behavior in obesity, the supporting evidence is inconsistent and is typically associated with methodological limitations. Notably, possible associations between sweet taste perception and measures of food reward remain undetermined.

Materials and methods

We conducted a cross-sectional analysis comparing 246 individuals with severe obesity and 174 healthy volunteers using a validated method for taste perception assessment. We included gustatory variables, namely intensity and pleasantness ratings of sour, salt, sweet, and bitter tastants, and taste thresholds assessed by electrogustometry. Reward-related feeding behavior, including hedonic hunger, food addiction, feeding behavior traits, and acceptance of foods and alcohol, was evaluated using self-rated scales for comparison with gustatory measures.

Result

In logistic regressions adjusted for age, gender, educational level, and research center, we found that a greater likelihood of belonging to the obesity group was associated with higher sweet intensity ratings (OR = 1.4, P = 0.01), hedonic hunger, food addiction symptoms, restrained and emotional eating (1.7 < OR ≤ 4.6, all P ≤ 0.001), and lower alcohol acceptance (OR = 0.6, P = 0.0002). Using principal component analysis, we found that while hedonic hunger, food addiction, and emotional eating were strongly interrelated, they were not associated with sweet intensity perception that, in turn, had a closer relationship with alcohol acceptance and restrained eating.

Conclusion

We found that individuals with obesity report higher sweet taste intensity ratings than healthy controls. Furthermore, while psychological measures of reward-related feeding behavior assess a common construct, sweet intensity perception may represent a different obesity-related dimension.

Revised Protein Sparing Diet in Obesity and Type 2 Diabetes Mellitus

Effective nutrition therapy is a pressing issue in obesity and type 2 diabetes mellitus (T2DM) management. As such, this research aimed to determine the performance of a revised dietary strategy built on the protein-sparing diet in obesity and type 2 diabetes mellitus with regard to obtaining a rapid and stable improvement in glucometabolic control, body weight, body composition, and energy metabolism when applying the strategy in just twenty-one days. The revised protein-sparing diet differs from the traditional protein-sparing modified fast (PSMF) because it does not include foods. The daily calorie intake of this diet is exclusively derived from Isolate whey protein in addition to a formulation of Isolate whey protein enriched with essential amino acids in free form, with the addition of lipids such as extra virgin olive oil and coconut oil as a source of medium chain fatty acids, where the latter is taken for only the first four days of the diet, together with the use, for the same duration, of extended-release metformin, as the only antihyperglycemic allowed. Anthropometric measurements, bioimpedance analysis, indirect calorimetry, and blood chemistry assessments were conducted at the beginning of the study, time 0 (T0), and at the end, time 1 (T1), i.e., on the 21st day. The main outcomes of the revised protein-sparing diet after only twenty-one days were a reduction in body weight with the predominant loss of visceral atherogenic abdominal fat and, therefore, a possible contextual reduction in ectopic fat deposits together with a simultaneous reduction in insulin resistance and normalization of insulin levels, maintenance of free fat mass and basal metabolism, restoration of metabolic flexibility, and improvement of the glucometabolic and lipidic parameters. These results demonstrate the promising potential of the revised protein-sparing diet as an "etiologic tool" in the integrated nutritional treatment of metabolic diseases such as obesity and type 2 diabetes mellitus.

Distinct factors associated with short-term and long-term weight loss induced by low-fat or low-carbohydrate diet intervention

To understand what determines the success of short- and long-term weight loss, we conduct a secondary analysis of dietary, metabolic, and molecular data collected from 609 participants before, during, and after a 1-year weight-loss intervention with either a healthy low-carbohydrate (HLC) or a healthy low-fat (HLF) diet. Through systematic analysis of multidomain datasets, we find that dietary adherence and diet quality, not just caloric restriction, are important for short-term weight loss in both diets. Interestingly, we observe minimal dietary differences between those who succeeded in long-term weight loss and those who did not. Instead, proteomic and gut microbiota signatures significantly differ between these two groups at baseline. Moreover, the baseline respiratory quotient may suggest a specific diet for better weight-loss outcomes. Overall, the identification of these dietary, molecular, and metabolic factors, common or unique to the HLC and HLF diets, provides a roadmap for developing individualized weight-loss strategies.

Fu Brick Tea Polysaccharides Prevent Obesity via Gut Microbiota-Controlled Promotion of Adipocyte Browning and Thermogenesis

The antiobesity efficacy and underlying mechanisms of polysaccharides extracted from Fu brick tea (FBTP) were investigated. An 8-week administration of FBTP dose-dependently inhibited increases in body weight and weights of the epididymal-, retroperitoneal- and inguinal-white adipose tissues and stimulated beige-fat development and brown adipose tissue-derived nonshivering thermogenesis in high-fat diet-induced obese mice. FBTP protected against obesity-associated abnormality in serum adiponectin and leptin, indicating its positive regulation of energy metabolism. FBTP reversed gut dysbiosis by enriching beneficial bacteria, for example, Lactobacillus, Parabacteroides, Akkermansia, Bifidobacterium, and Roseburia. Results from the fecal microbiota transplantation further confirmed that FBTP-induced microbial shifts contributed to adipose browning and thermogenesis, thereby alleviating host adiposity, glucose homeostasis, dyslipidemia, and its related hepatic steatosis. Our study demonstrates the great potential of FBTP with prebiotic-like activities in preventing diet-induced obesity and its related metabolic complications via gut microbiota-derived enhancement of fat burning and energy expenditures.

The evolving view of thermogenic fat and its implications in cancer and metabolic diseases

The incidence of metabolism-related diseases like obesity and type 2 diabetes mellitus has reached pandemic levels worldwide and increased gradually. Most of them are listed on the table of high-risk factors for malignancy, and metabolic disorders systematically or locally contribute to cancer progression and poor prognosis of patients. Importantly, adipose tissue is fundamental to the occurrence and development of these metabolic disorders. White adipose tissue stores excessive energy, while thermogenic fat including brown and beige adipose tissue dissipates energy to generate heat. In addition to thermogenesis, beige and brown adipocytes also function as dynamic secretory cells and a metabolic sink of nutrients, like glucose, fatty acids, and amino acids. Accordingly, strategies that activate and expand thermogenic adipose tissue offer therapeutic promise to combat overweight, diabetes, and other metabolic disorders through increasing energy expenditure and enhancing glucose tolerance. With a better understanding of its origins and biological functions and the advances in imaging techniques detecting thermogenesis, the roles of thermogenic adipose tissue in tumors have been revealed gradually. On the one hand, enhanced browning of subcutaneous fatty tissue results in weight loss and cancer-associated cachexia. On the other hand, locally activated thermogenic adipocytes in the tumor microenvironment accelerate cancer progression by offering fuel sources and is likely to develop resistance to chemotherapy. Here, we enumerate current knowledge about the significant advances made in the origin and physiological functions of thermogenic fat. In addition, we discuss the multiple roles of thermogenic adipocytes in different tumors. Ultimately, we summarize imaging technologies for identifying thermogenic adipose tissue and pharmacologic agents via modulating thermogenesis in preclinical experiments and clinical trials.

The Data Behind Popular Diets for Weight Loss

Both scientific evidence and popular diet trends have sought to identify the ideal diet for weight loss with strategies focused on either restricting carbohydrates or fat. While there is a strong physiologic rationale for either carbohydrate restriction or fat restriction to achieve a calorie deficit needed for weight loss, evidence from randomized controlled trials suggest either type of diet is effective for weight loss. The level of adherence, rather than macronutrient content, is the driver of successful weight loss.

Obesity: an evolutionary context

People completely lacking body fat (lipodystrophy/lipoatrophy) and those with severe obesity both show profound metabolic and other health issues. Regulating levels of body fat somewhere between these limits would, therefore, appear to be adaptive. Two different models might be contemplated. More traditional is a set point (SP) where the levels are regulated around a fixed level. Alternatively, dual-intervention point (DIP) is a system that tolerates fairly wide variation but is activated when critically high or low levels are breached. The DIP system seems to fit our experience much better than an SP, and models suggest that it is more likely to have evolved. A DIP system may have evolved because of two contrasting selection pressures. At the lower end, we may have been selected to avoid low levels of fat as a buffer against starvation, to avoid disease-induced anorexia, and to support reproduction. At the upper end, we may have been selected to avoid excess storage because of the elevated risks of predation. This upper limit of control seems to have malfunctioned because some of us deposit large fat stores, with important negative health effects. Why has evolution not protected us against this problem? One possibility is that the protective system slowly fell apart due to random mutations after we dramatically reduced the risk of being predated during our evolutionary history. By chance, it fell apart more in some people than others, and these people are now unable to effectively manage their weight in the face of the modern food glut. To understand the evolutionary context of obesity, it is important to separate the adaptive reason for storing some fat (i.e. the lower intervention point), from the nonadaptive reason for storing lots of fat (a broken upper intervention point). The DIP model has several consequences, showing how we understand the obesity problem and what happens when we attempt to treat it.

Changing clinical management of NAFLD in Asia

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, affecting approximately 25% of the world's population. Recently, because of the sedentary lifestyle and overnutrition resulting from urbanisation, the burden of NAFLD has rapidly increased in many Asian countries. Currently, the prevalence of NAFLD in Asia is approximately 30%, as is the case in many Western countries. In Asia, the prevalence and presentation of NAFLD vary widely across regions because of the substantial diversity in race, socioeconomic status and living environment. Furthermore, the dual aetiology of fatty liver, particularly with viral hepatitis in Asia, makes it complex and challenging to manage. Because Asians are likely to have central adiposity and insulin resistance, approximately 7%-20% of non-obese Asians with body mass indexes of less than 25 kg/m² are estimated to have NAFLD. Accumulating evidence indicates that NAFLD is associated with various extrahepatic comorbidities such as cardiovascular disease, chronic kidney disease, malignancy, in addition to liver-specific complications. Therefore, NAFLD should be managed as a multisystem disease in conjunction with metabolic syndrome. Lifestyle modification remains the basis of NAFLD management, but few patients can achieve adequate weight loss and maintain it long term. While various pharmacological agents are in phase 3 trials for steatohepatitis, Asian patients are underrepresented in most trials. This article reviews the epidemiological trends, clinical features, optimal assessment and current management practices for NAFLD in Asia.

Polysaccharides from Callerya speciosa alleviate metabolic disorders and gut microbiota dysbiosis in diet-induced obese C57BL/6 mice

Callerya speciosa ("Niu Dali" in Chinese) is a well-known edible plant in Southeast China. C. speciosa roots contain a high level of polysaccharides, which have been reported to show multiple health-promoting effects. In the current study, the anti-obesity effects of a crude extract of C. speciosa polysaccharides (NP) and its underlying mechanisms of action are investigated. C57BL/6 mice were divided into three groups and fed either a standard diet or a high-fat diet (HFD). The HFD + NP group mice received oral administration of NP (100 mg per kg per day) every other day for 10 weeks. NP supplementation alleviated HFD-induced diabetic biomarkers including body weight gain, hyperlipidemia, liver steatosis, and adipocyte hypertrophy. Western blot and RT-PCR analyses revealed that NP inhibited hepatic de novo lipogenesis and adipogenesis (i.e. decreased expression of Srebp1c, Fas, Cebpα, and Pparγ), stimulated adipocyte lipolysis (enhanced mRNA expression of Hsl and Mgl), and attenuated HFD-induced hepatic inflammation (decreased expression of TNF-α and NF-κB p65). Furthermore, 16S rDNA and GC-MS analyses showed that NP supplementation restored the Firmicutes/Bacteroidetes proportion, elevated colon-derived SCFAs, especially acetic acid content, and increased the relative abundance of genera associated with SCFA production in HFD-fed mice. Findings from this study suggest that NP alleviated HFD-induced obesity in a mouse model, which was possibly due to its ameliorative effects on diet-induced gut dysbiosis. Polysaccharides from C. speciosa are promising prebiotics and they may be further developed as functional foods for the management of obesity.

Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models

The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake (“eat less”) and increase energy expenditure (“move more”). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that this approach rests on an erroneous paradigm. A new formulation of the energy balance model (EBM), like prior versions, considers overeating (energy intake > expenditure) the primary cause of obesity, incorporating an emphasis on “complex endocrine, metabolic, and nervous system signals” that control food intake below conscious level. This model attributes rising obesity prevalence to inexpensive, convenient, energy-dense, “ultra-processed” foods high in fat and sugar. An alternative view, the carbohydrate-insulin model (CIM), proposes that hormonal responses to highly processed carbohydrates shift energy partitioning toward deposition in adipose tissue, leaving fewer calories available for the body’s metabolic needs. Thus, increasing adiposity causes overeating to compensate for the sequestered calories. Here, we highlight robust contrasts in how the EBM and CIM view obesity pathophysiology and consider deficiencies in the EBM that impede paradigm testing and refinement. Rectifying these deficiencies should assume priority, as a constructive paradigm clash is needed to resolve long-standing scientific controversies and inform the design of new models to guide prevention and treatment. Nevertheless, public health action need not await resolution of this debate, as both models target processed carbohydrates as major drivers of obesity.