Long-term weight-loss maintenance: a meta-analysis of US studies

A simple action reduces high-fat diet intake and obesity in mice

Diets that are high in fat cause overeating and weight gain in multiple species of animals, suggesting that high dietary fat is sufficient to cause obesity. However, high-fat diets are typically provided freely to animals in obesity experiments, so it remains unclear whether high-fat diets would still cause obesity if these diets required more effort to obtain. We hypothesized that unrestricted access to high-fat diets is important for these diets to induce overeating and that requiring mice to perform small amounts of work to obtain a high-fat diet would reduce calorie intake and associated weight gain. To test this hypothesis, we developed a novel home-cage-based feeding device that provided the high-fat diet in two conditions: either freely or after mice poked their noses into a port one time-a simple action that is easy for them to do. Consistent with our hypothesis, requiring mice to nose-poke reduced high-fat diet intake and nearly completely prevented weight gain. Requiring mice to nose-poke also reduced low-fat grain-based pellet intake, confirming that this is a general mechanism governing food choice and not something specific to a high-fat diet. We conclude that unrestricted access to food promotes overeating and that requiring a simple action such as a nose-poke can reduce overeating and weight gain in mice. Our results may have implications for why overeating and obesity are common in modern food environments, which are often characterized by easy access to low-cost unhealthy foods.

Dietary interventions for the management of type 2 diabetes mellitus in childhood and adolescence: A systematic review

AIMS

Despite the alarming increasing incidence of type 2 diabetes mellitus (T2DM) in children and young People (CYP), and its associated morbidities and poor long-term prognosis, there remains uncertainty in its management. Dietary interventions have been shown to be effective in adults with T2DM, but little is known about their effectiveness in CYP. The aim of this systematic review is to provide up-to-date evidence regarding dietary interventions for T2DM in childhood and adolescence.

METHODS

Five databases Embase, MEDLINE, CENTRAL, Web of Science and CINAHL were searched from January 2000 to May 2023 for all studies involving dietary interventions in CYP under 19 years with T2DM. The primary outcome was glycaemic control as measured by HbA1c.

RESULTS

Of 8352 search results, five papers met inclusion criteria. No randomised controlled trials were identified. Two interventional studies (n = 28) found very low energy diets (VLED) were associated with reduced HbA1c (16 mmol/mol (3.6%) reduction after 8 weeks), decreased requirement for pharmacotherapy and weight loss. However, benefits to HbA1c were not sustained over 2 years. From the observational studies, the most frequent self-reported dietary strategies were limiting sweets and increasing fruit/vegetable intake, but efficacy was limited. Limiting fat intake was associated with improved HbA1c in women.

CONCLUSIONS

There is limited evidence and a lack of robust clinical trials to support the effectiveness of dietary interventions for CYP-onset T2DM. With evidence of benefit in adulthood and encouraging initial results in the young, it is imperative that fully powered randomised trials with longer follow-up are undertaken to determine efficacy.

Bridging the gap in obesity research: A consensus statement from the European Society for Clinical Investigation

BACKGROUND

Most forms of obesity are associated with chronic diseases that remain a global public health challenge.

AIMS

Despite significant advancements in understanding its pathophysiology, effective management of obesity is hindered by the persistence of knowledge gaps in epidemiology, phenotypic heterogeneity and policy implementation.

MATERIALS AND METHODS

This consensus statement by the European Society for Clinical Investigation identifies eight critical areas requiring urgent attention. Key gaps include insufficient long-term data on obesity trends, the inadequacy of body mass index (BMI) as a sole diagnostic measure, and insufficient recognition of phenotypic diversity in obesity-related cardiometabolic risks. Moreover, the socio-economic drivers of obesity and its transition across phenotypes remain poorly understood.

RESULTS

The syndemic nature of obesity, exacerbated by globalization and environmental changes, necessitates a holistic approach integrating global frameworks and community-level interventions. This statement advocates for leveraging emerging technologies, such as artificial intelligence, to refine predictive models and address phenotypic variability. It underscores the importance of collaborative efforts among scientists, policymakers, and stakeholders to create tailored interventions and enduring policies.

DISCUSSION

The consensus highlights the need for harmonizing anthropometric and biochemical markers, fostering inclusive public health narratives and combating stigma associated with obesity. By addressing these gaps, this initiative aims to advance research, improve prevention strategies and optimize care delivery for people living with obesity.

CONCLUSION

This collaborative effort marks a decisive step towards mitigating the obesity epidemic and its profound impact on global health systems. Ultimately, obesity should be considered as being largely the consequence of a socio-economic model not compatible with optimal human health.

Low- or No-Energy Sweeteners and Body Weight Management: Dissecting a "Minor" Effect

Nonnutritive sweeteners were introduced on the market over a century ago to displace the calories of added sugars in foods and beverages and, therefore, facilitate weight loss. In spite of their widespread use, obesity has reached epidemic proportions. The present paper addresses this apparent paradox. Low- or no-energy sweeteners (LNES) are a small group of widely different substances that can be used to modify one single aspect of energy intake, i.e., consumption of added sugars. Their potential benefits for weight management can be predicted by energy balance equations. Decades of research confirm that LNES affect weight via a purely nutritional mechanism, in proportion of their actual displacement of sugar energy. LNES allow a substantial decrease in energy density of beverages (as opposed to solid foods) and can be maximally effective in consumers of sugar-containing drinks. Their average effect is robust but modest (1-2-kg weight loss) compared to comprehensive weight-loss programs (±5 kg), medication, or surgery (+10% of initial weight). Other benefits of LNES include sensory-specific satiety for sweet foods, improved diet adherence, and facilitation of weight-loss maintenance. Whether these effects are considered minor or major benefits in the present obesogenic context is a matter of individual definition.

Does weighted vest use during weight loss influence long-term weight loss maintenance? A pilot study in older adults living with obesity and osteoarthritis

The purpose of this study was to explore whether and how gravitational loading during intentional weight loss (WL) influences subsequent weight regain. Pilot data come from a convenience sample of 18 older adults (70.4 ± 3.1 years, 83% women, 78% white) with obesity who participated in a 6-month WL intervention and also returned for 24-month follow-up assessment. Participants were originally assigned to 6-months of caloric restriction plus 10 h/day weighted vest use (WL+VEST; n = 9) or caloric restriction only (WL Only; n = 9). Body weight (BW) and resting metabolic rate (RMR) were collected at baseline, 6, and 24 months. WL+VEST and WL Only participants lost significant and similar amounts of BW by 6-months [WL+VEST: -11.2 kg (95% CI: -14.6, -7.7) versus WL Only: -10.3 kg (95% CI: -13.7, -6.8)]; p = 0.71. By 24-months, the WL+VEST group regained approximately half of lost BW [-4.8 kg from baseline (95% CI: -9.6, 0.1)], while the WL Only group regained all lost BW [+0.9 kg from baseline (95% CI: -3.9, 5.8)]; p = 0.10. Change in RMR from baseline to 6 months was -16.3 (95% CI: -100.8, 68.2) kcal/day and -237.5 (95% CI: -321.9, -153.0) kcal/day for the WL+VEST and WL Only groups, respectively (p < 0.01); and was modestly and inversely associated with change in BW from 6 to 24 months (r = -0.39, p = 0.11). Pilot data signal weighted vest use during caloric restriction may be associated with reduced weight regain via preserved RMR. Study Overview and Results. Created with BioRender.com.

Advancing Diabetes Management and Glycemic Control While Exploring CagriSema's Impact on Obesity Management

Diabetes is a complex metabolic disorder affecting over 37 million people in the United States. Without proper management, diabetes can lead to a myriad of complications, including cardiovascular disease, kidney failure, and vision loss. Obesity is a major contributor to type 2 diabetes, but genetic and physiological factors make weight loss difficult, necessitating medication management for both conditions. Government-approved weight loss medications, including glucagon-like peptide-1 agonists and amylin analogs, have proven to be effective for both conditions. However, intensive glycemic control involving antidiabetic medications, while beneficial for reducing diabetic complications, can often precipitate hypoglycemic events, which are characterized by cardiac arrhythmias, coma, confusion, and even mortality. A new drug under investigation, CagriSema, combines cagrilintide, an amylin analog, with semaglutide, a glucagon-like peptide-1 agonist. This drug is being marketed as a safe and potentially superior medication to lower both Hemoglobin A1c and body weight. In this article, the pathophysiology, current guidelines, and management of diabetes will be reviewed, with an emphasis on the clinical evidence for tight glucose control and avoiding hypoglycemic events. Following this, an overview of recent trials on antidiabetic medications, including those involving CagriSema, will be presented, along with prospects for future trials in this promising area of research.

Fasting appetite-related gut hormone responses after weight loss induced by calorie restriction, exercise, or both in people with overweight or obesity: a meta-analysis

OBJECTIVES

Altered appetite-related gut hormone concentrations may reflect a physiological adaptation facilitating weight regain after weight loss. This review investigates hormonal changes after weight loss achieved through calorie restriction (CR), exercise (EX), or both combined (CREX).

METHODS

A systematic search of PubMed (MEDLINE), EMBASE, SPORTDiscus, Cochrane Library, Web of Science, and ClinicalTrials.gov was conducted to identify randomised controlled trials (RCTs) and non-RCTs reporting in a fasting state either pre- and post-intervention appetite-related hormone concentrations or the changes therein after weight loss. The hormones examined were ghrelin, peptide tyrosine tyrosine (PYY), glucagon-like peptide -1 (GLP-1), and cholecystokinin (CCK), in their total and/or active form. Standardised mean differences (SMD) were extracted as the effect size.

RESULTS

127 studies were identified: 19 RCTs, 108 non-RCTs, 1305 and 4725 participants, respectively. In response to weight loss induced by CR, EX or CREX, the meta-analysis revealed an increase in total ghrelin from both RCTs (SMD: 0.55, 95% CI: 0.07-1.04) and non-RCTs (SMD: 0.24, 95% CI: 0.14-0.35). A decrease in acylated ghrelin was identified for RCTs (SMD: -0.58, 95% CI: -1.09 to -0.06) but an increase was observed for non-RCTs (SMD: 0.15, 95% CI: 0.03 to 0.27). Findings also revealed a decrease in PYY (total PYY: SMD: -0.17, 95%CI: -0.28 to -0.06; PYY3-36: SMD: -0.17, 95%CI: -0.32 to -0.02) and active GLP-1 (SMD: -0.16, 95% CI: -0.28 to -0.05) from non-RCTs. Changes in hormones did not differ among the three interventions when controlling for weight loss. Meta-regression indicated that greater weight loss was associated with a greater increase in total ghrelin.

CONCLUSIONS

Weight loss induced by CR, EX, or CREX elicits an increase in total ghrelin, but varied responses in other appetite-related hormones. The extent of weight loss influences changes in appetite-related gut hormone concentrations.

The Effect of 4:3 Intermittent Fasting on Weight Loss at 12 Months : A Randomized Clinical Trial

BACKGROUND

Long-term (≥12 months) randomized trials evaluating the efficacy of intermittent fasting (IMF) as a dietary weight loss strategy are limited. Furthermore, no studies have compared IMF versus daily caloric restriction (DCR) when both interventions are provided in the context of a guidelines-based behavioral weight loss program.

OBJECTIVE

To compare the effects of 4:3 IMF versus DCR on changes in weight at 12 months, with comprehensive behavioral support provided to both groups.

DESIGN

Randomized clinical trial. (ClinicalTrials.gov: NCT03411356).

SETTING

Denver, Colorado, and surrounding metropolitan area.

PARTICIPANTS

Adults aged 18 to 60 years with body mass index (BMI) of 27 to 46 kg/m2.

INTERVENTION

The IMF group was instructed to restrict energy intake by 80% on 3 nonconsecutive days per week, with ad libitum intake (no restriction) the other 4 days (4:3 IMF). The DCR group was instructed to reduce daily energy intake by 34% to match the weekly energy deficit of 4:3 IMF. Both groups received a high-intensity comprehensive behavioral weight loss program that included group-based behavioral support and a recommendation to increase moderate-intensity physical activity to 300 minutes per week.

MEASUREMENTS

The primary outcome was change in body weight (in kilograms) at 12 months.

RESULTS

Of the 165 (4:3 IMF, n = 84; DCR, n = 81) randomly assigned participants (mean age, 42 years [SD, 9]; mean BMI, 34.1 kg/m2 [SD, 4.4]; 73.9% female), 125 completed the trial. In an intention-to-treat analysis, 4:3 IMF showed greater reductions in weight than DCR at 12 months (mean difference, 2.89 kg [95% CI, 5.65 to 0.14 kg]; P = 0.040).

LIMITATION

Limited generalizability.

CONCLUSION

Compared with DCR, 4:3 IMF resulted in modestly greater weight loss among adults with overweight or obesity enrolled in a 12-month, high-intensity, comprehensive behavioral weight loss program.

PRIMARY FUNDING SOURCE

National Institute of Diabetes and Digestive and Kidney Diseases.

Five-year follow-up of a randomized weight loss trial on a digital health behaviour change support system

BACKGROUND

The weight regain after successful weight loss is a common challenge. This study aimed to assess the long-term effectiveness of a web-based health behaviour change support system (HBCSS) utilizing persuasive systems design (PSD) and methods of cognitive behavioural therapy (CBT). We have previously demonstrated the two-year effectiveness of the HBCSS.

METHODS

In total, 532 participants with overweight or obesity (BMI 27-35 kg m-2) were split into three groups with different intensities of intervention: CBT-based group counselling, self-help guidance (SHG), and usual care. These groups were further divided into HBCSS and non-HBCSS groups. The HBCSS was a 52-week programme. The follow-up took five years in total.

RESULTS

Mean weight change (%) (95% CI) from baseline among HBCSS and non-HBCSS users was 1.5 (-0.02 to 2.9), p = 0.056 and 1.9 (0.3-3.3), p = 0.005, respectively, at five years. Of the six groups, the SHG group without HBCSS had a statistically significant increase in weight (%) from baseline at five years (3.1, 95% CI 0.6 to 5.6, p = 0.010). The other groups did not have a significant increase in weight. There was no significant difference between groups at five years in weight. Fewer blood pressure medications were started over the five-year period in HBCSS group (p = 0.046).

CONCLUSION

The 12-month HBCSS intervention was not able to maintain reduced weight better than non-HBCSS at 5 years. However, there were significant weight difference favouring HBCSS over the whole 5-year period. The decrease in the need for antihypertensives suggests that the significant weight loss by HBCSS at early years has a health-promoting legacy effect.

Impact of child summertime obesity interventions on body mass index and weight-related behaviors: A systematic review and meta-analysis

INTRODUCTION

Obesity during childhood is a critical public health issue. The summer break from school is a time when children are prone to accelerated weight gain. We aimed to investigate how obesity prevention or treatment programs implemented over the summer affect anthropometric measures or weight-related behaviors.

METHODS

Published studies examining the impact of obesity prevention/treatment interventions targeting the summer with anthropometric or weight-related behaviors in children (5-18 years old) were identified using systematic searches of Medline, Cochrane, Scopus, CINAHL, PsycINFO, and EMBASE until April 2024. The summarized effect estimate was computed by applying the random-effects approach. The evidence certainty was assessed using GRADE.

RESULTS

Forty-seven studies were identified for inclusion. The majority of studies identified focused on physical activity and dietary habits. Only six studies that examined the effects of prevention interventions on weight, body mass index (BMI), and waist circumference (WC) were meta-analyzed. There was no evidence that prevention interventions impacted children's weight, BMI, and WC. However, most of the studies included in the systematic review indicated beneficial effects of interventions for anthropometric measures.

CONCLUSION

There was no evidence that summertime obesity interventions targeting physical activity and dietary intake were effective in the prevention of obesity in children.

Semaglutide-induced weight loss improves mitochondrial energy efficiency in skeletal muscle

OBJECTIVE

Glucagon-like peptide-1 receptor agonists (e.g., semaglutide) potently induce weight loss, thereby reducing obesity-related complications. However, weight regain occurs when treatment is discontinued. An increase in skeletal muscle oxidative phosphorylation (OXPHOS) efficiency upon diet-mediated weight loss has been described, which may contribute to reduced systemic energy expenditure and weight regain. We set out to determine the unknown effect of semaglutide on muscle OXPHOS efficiency.

METHODS

C57BL/6J mice were fed a high-fat diet for 12 weeks before receiving semaglutide or vehicle for 1 or 3 weeks. The rates of ATP production and oxygen (O2) consumption were measured via high-resolution respirometry and fluorometry to determine OXPHOS efficiency in muscle at these two time points.

RESULTS

Semaglutide treatment led to significant reductions in fat and lean mass. Semaglutide improved skeletal muscle OXPHOS efficiency, measured as ATP produced per O2 consumed in permeabilized muscle fibers. Mitochondrial proteomic analysis revealed changes restricted to two proteins linked to complex III assembly (LYRM7 and TTC19; p < 0.05 without multiple corrections) without substantial changes in the abundance of OXPHOS subunits.

CONCLUSIONS

These data indicate that weight loss with semaglutide treatment increases skeletal muscle mitochondrial efficiency. Future studies could test whether it contributes to weight regain.

Systematic Review and Meta-analysis of Randomized Clinical Trials Comparing Time-Restricted Eating With and Without Caloric Restriction for Weight Loss

CONTEXT

Although it is well established that caloric restriction (CR) is the primary driver of weight loss, circadian-driven metabolic benefits have been recognized as possibly enhancing the effects of CR. Time-restricted eating (TRE) has emerged as a promising approach in this context.

OBJECTIVE

We conducted a systematic review and meta-analysis to compare the effects of TRE with isocaloric diet controls (analysis 1) and non-isocaloric controls (analysis 2) on anthropometric and body-composition parameters in adults with overweight or obesity.

DATA SOURCES

A search was carried out in the Medline, LILACS, Embase, and CENTRAL databases using Medical Subject Heading (MeSH) and similar terms such as "Obesity," "Obesity, Abdominal," "Time-restricted eating," "Body weight," "Changes in body weight," and others.

DATA EXTRACTION

We included 30 studies involving a total of 1341 participants. Studies were screened based on titles and abstracts followed by full-text reading, and data were extracted from eligible studies using a pre-established form. All these steps were performed by 2 authors independently and blinded, with discrepancies resolved by a third author.

DATA ANALYSIS

The results of main findings revealed that, in studies using non-isocaloric controls, the TRE group showed significant reductions in body weight (BW) (mean difference [MD]: -2.82 kg; 95% CI: -3.49, -2.15), fat mass (FM) (MD: -1.36 kg; 95% CI: -2.09, -0.63), and fat-free mass (FFM) (MD: -0.86 kg; 95% CI: -1.23, -0.49). In studies that used isocaloric control strategies, the TRE group showed significant reductions in BW (MD: -1.46 kg; 95% CI: -2.65, -0.26), FM (MD: -1.50 kg; 95% CI: -2.77, -0.24), and FFM (MD: -0.41 kg; 95% CI: -0.79, -0. 03).

CONCLUSION

TRE yields favorable anthropometric and clinical outcomes, even when intake is isocaloric between the intervention and control groups. This result suggests that circadian effects may enhance the impact of CR on excess weight.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022301594.

Maintenance of time-restricted eating and high-intensity interval training in women with overweight/obesity 2 years after a randomized controlled trial

Time-restricted eating (TRE) and high-intensity interval training (HIIT) improve cardiometabolic health in individuals with overweight/obesity, with high adherence rates in supervised settings. Long-term maintenance of TRE and HIIT in real-world settings is unknown. In our previous TREHIIT trial, 131 women (body mass index (BMI) ≥ 27 kg/m2) were randomized to 7 weeks of TRE (eating window 10-h/day), HIIT (3 sessions/week), a combination (TREHIIT), or no intervention (CON). We investigated self-reported continuation of TRE and/or HIIT after 2 years. Fifty-nine participants (39.0 years (standard deviation (SD) 6.1), BMI 30.7 kg/m2 (SD 4.2)) attended the follow-up. Of those who completed the 7-week TRE or HIIT intervention, 46% maintained TRE and 45% continued HIIT for 2 years. There were no statistically significant (at p < .01) between-group differences in cardiometabolic outcomes, but non-significant lower body mass in HIIT (-4.2 kg, 95% confidence interval (CI), -7.7 to -0.7, p = .019) and visceral fat in TREHIIT (-18 cm2, CI, -33 to -4, p = .015) versus CON. After 2 years, HIIT and TREHIIT had ~ 4 kg lower fat mass and ~ 20 cm² lower visceral fat (both p < .001) compared with baseline. A short-term TRE and HIIT intervention may promote long-term lifestyle changes and health benefits. Future studies should collect objective adherence data to understand long-term maintenance of TRE and HIIT.

Effects of 12 Months of Structured Physical Activity Program and 18-Month Follow-Up Period on Body Composition, Physical Capacities, and Physical Activity Levels in Adults with Obesity

(1) Background: Individuals with obesity tend to stop exercising after the completion of a structured training program. Thus, the aim of the present study was to assess adherence and body composition, cardiorespiratory fitness, physical activity levels, and physical and mental health after a 12-month exercise program and an 18-month follow-up period in a group of male adults with obesity. (2) Methods: Thirty-four adults with obesity were evaluated before (T0) and after (T3) a 3-month combined training (COMB). After that, they followed a maintenance program with low-intensity aerobic activity for three months. Then, they were recalled for a 6-month training program including thresholds (THR) training until the end of the study (T12). Finally, they participated in a 18-months follow-up period that included suggestions for healthy lifestyles, which ended with assessments (T30). Thus, the assessments were carried out at the beginning and end of the first training protocol (T0 and T3), at the beginning and end of the second training protocol (T6 and T12) and 18 months after the end of the training program (T30). At all time points, body composition (i.e., BMI, fat mass [FM] and fat-free mass [FFM]), physical capacities (i.e., V̇O2max), and physical habits (i.e., International Physical Activity Questionnaire (IPAQ) and Short-Form 12 (SF-12, for physical, P, and mental, M, indices) were measured. (3) Results: Fifteen out of thirty-four participants (42.8%) (age 42.8 ± 8.1 y) completed this study. At T30, participants increased their V̇O2max (3.07 ± 0.46 vs. 3.67 ± 0.60 L·min-1, p < 0.001), IPAQ TOT score (396 (2888) vs. 1356 (9144), p = 0.006), and SF12_MI score (41.1 ± 8.9 pt vs. 48.6 ± 11.0 pt) compared to T0. Furthermore, multivariate analysis showed that decrease in BMI was largely associated with the increase in the SF 12_PI questionnaire (0.032). Similarly, the decrease in %FM and the increase in V̇O2max were related with the increase in IPAQ tot (p < 0.001) and SF 12_MI (p < 0.001) scores. (4) Conclusions: 42.8% (15 out of 34) of the initial participants completed the follow-up test at T30 and maintained higher V̇O2max values than at T0. Conversely, their physical characteristics returned to baseline. The improvement in V̇O2max, compared to T0, correlated with maintaining high activity levels and with improved physical and mental well-being. In summary, it is recommended that people with obesity follow a structured physical activity program, as this leads to an improvement in physical capacities and physical and mental well-being. A personalized and monitored approach can lead to greater adherence to treatment and more effective long-term outcomes.

The Impact of Bias and Stigma on Patient Referral for Metabolic/Bariatric Surgery: An Algerian Experience

Obesity is a chronic disease causing a major public health challenge, particularly in Algeria, yet in patient referrals for metabolic/bariatric surgery (MBS), the most effective treatment remain low. This study aims to analyze the factors influencing referrals for MBS, focusing on the impact of obesity bias and stigma among primary care physicians. A survey questionnaire was sent electronically to 250 physicians across four regions in Algeria. The questionnaire evaluated their knowledge, attitudes, perceptions, and practices regarding MBS including questions on indications for MBS, operative techniques, physicians' attitudes toward patients with obesity, and factors influencing patient referrals for MBS. Survey response rate was 37.2% (93/250 physicians), most physicians (89%) recognized obesity as a chronic disease, and majority (60%) of physicians were aware that hunger regulation centers are involuntary and located in the hypothalamus; 34.4% believed that lifestyle changes were sufficient to treat severe obesity. Significant knowledge gaps were observed regarding MBS indications, 83% expressed a willingness to help their patients achieve ideal weight, but only 10% of physicians referred patients for MBS. Many physicians showed negative attitudes toward patients with obesity, and 68% held stereotypes about obesity, attributing it to a lack of personal willpower. These stigmas may have contributed to the low referral rates for MBS. Additional barriers were economic barriers, such as the high cost of MBS and limited or absent insurance coverage. A lack of knowledge about metabolic/bariatric surgery, coupled with stigmatizing attitudes and economic constraints, hinders patient referrals for MBS, which is the most effective treatment for severe obesity. The study highlights the need for more education of primary care physicians, promoting an empathetic and interprofessional approach and implementing health policies that improve financial accessibility to MBS in Algeria.

Tackling the complexity of obesity in the US through adaptation of public health strategies

Obesity prevalence continues to rise in the US despite more than two decades of recommendations and guidelines for its prevention and management. The encouragement of individuals to adopt a healthy diet and lifestyle has remained the focus of clinical interventions and recommendations despite these efforts alone proving ineffective for long-term weight management. There are many recognized barriers to obesity prevention and management in community and clinical settings including political factors, social determinants of health, weight bias and stigma, and inequities in access to treatment and insurance coverage. We discuss these barriers in more detail and attempt to identify areas where public health and healthcare approaches can be better aligned, allowing for better advocating by public health officials to enable a more meaningful and population-level change in obesity prevention and management in the US.

Artificial intelligence in anti-obesity drug discovery: unlocking next-generation therapeutics

Obesity, a multifactorial disease linked to severe health risks, requires innovative treatments beyond lifestyle changes and current medications. Existing anti-obesity drugs face limitations regarding efficacy, side effects, weight regain and high costs. Artificial intelligence (AI) is emerging as a pivotal tool in drug discovery, expediting the identification of novel drug candidates and optimizing treatment strategies. This review examines AI's potential in developing next-generation anti-obesity therapeutics, with a focus on glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and their role in discovering anti-obesity peptides. Additionally, it explores integration challenges and offers future perspectives on leveraging AI to reshape the landscape of anti-obesity drug discovery.

Impact of Lifestyle Changes on Body Weight Gain During Nationwide Lockdown Due to COVID-19 Pandemic

Background: During the coronavirus disease 2019 (COVID-19) pandemic, people in Japan were urged to stay at home as much as possible, and this resulted in significant changes in lifestyle behavior. The new lifestyle included factors affecting both energy intake and energy consumption, and it is now thought that weight gain during the lockdown was the result of complex effects. The aim of this study was to determine the relationships among lifestyle habits, laboratory data, and body weight gain during the lockdown using medical check-up data. Methods: A total of 3789 individuals who had undergone consecutive medical check-ups during the period from 2018 to 2020 were included in this study. Participants whose body weight had increased by 5% or more were divided into two groups: a before-lockdown group (participants who had gained weight between 2018 and 2019) and an after-lockdown group (participants who had gained weight between 2019 and 2020). Physical measurements, laboratory data, and answers to six questions about lifestyle habits, for which information was obtained from the records from medical check-ups, were compared in the two groups. Results: There was no significant difference between the distribution of weight changes in 2018-2019 before the lockdown and the distribution of weight changes in 2019-2020 after the lockdown. The before-lockdown and after-lockdown groups both included about 7% of the total participants (279 and 273 participants, respectively). Diastolic blood pressure and levels of AST, ALT, and LDL-C were significantly higher in the after-lockdown group than in the before-lockdown group. The percentages of participants with alcohol consumption and exercise habits were significantly higher in the after-lockdown group than in the before-lockdown group, and an analysis by gender showed that the differences were significant for women but not for men. Conclusions: The distributions of weight changes before and during the COVID-19 pandemic were similar. Exercise habits and alcohol consumption might have been unique factors causing weight gain during the COVID-19 pandemic, particularly in women. Our findings suggest that the impact of behavioral restrictions and lifestyle changes during a pandemic may be different in men and women.

Reduced food cravings correlated with a 24-month period of weight loss and weight maintenance

Food cravings increase calorie-dense food intake, contributing to weight gain. Although reductions in food cravings are frequently reported during weight loss, it remains unclear whether these changes are sustained during weight maintenance. The study objective was to investigate associations between food cravings and weight changes in a 12-month weight loss trial followed by 12 months of maintenance. Thirty adults participated in a dietary weight loss program that included craving coping strategies, daily weigh-ins and food craving assessments every six months. Twenty-four and twenty participants remained at 12 and 24 months, respectively. Craving frequency and traits decreased during weight loss and stabilized during maintenance. Changes in general food (FCI), sweet, and carbohydrate cravings at 6 months predicted weight change over 24 months. The craving-weight correlations persisted during weight maintenance. Participants achieving >5 % weight loss at 24 months (n = 13) consistently reduced craving traits and FCI, while those with <5 % weight loss (n = 7) showed no significant change. Differences between the groups become significant at 18 and 24 months for craving traits and at 24 months for FCI. Participants who included craved foods into a balanced meal (n = 16) achieved greater weight loss and greater reduction in sweet and high-fat food cravings compared to those who did not (n = 8) at 12 months. This study showed a strong correlation between successful weight loss/maintenance and reduced food cravings, whereas users of the craving control strategy achieved greater weight loss. These results suggest that weight loss reduces cravings, and controlling cravings, in turn, further accelerates weight loss.

Interhemispheric paired associative stimulation targeting the bilateral prefrontal cortex of subjects with obesity and food addiction modulates food-related emotional reactivity and associated brain activity

PURPOSE

Behavioral and neurobiological abnormalities in addiction and obesity have led to the theory of food addiction in obesity (FAOB) and brain-behavior association studies. Transcranial magnetic stimulation (TMS) studies and treats various brain disorders. Cortico-cortical paired associative stimulation TMS protocol, in which left lateral prefrontal cortex (LPFC) stimulation follows right LPFC stimulation, can reduce emotional reactivity to visual triggers and modulate prefrontal asymmetry in healthy adults. Accordingly, we examined the effects of acute ccPAS on food cravings and brain responses in FAOB.

METHODS

Twenty-two adults (12 Active, 10 Sham) with FAOB participated in this single-blind, sham-controlled pilot study. Electroencephalogram was recorded during rest and a Food Stroop task, which were conducted before and after a single active or sham ccPAS session, consisting of 600 paired stimulation pulses of the right, then left LPFC, with inter-pulse interval of 8ms and a 3sec inter-pair-interval. Stroop bias changes following exposure to food images, alterations in the associated (emotionally laden) late positive event-related component (LPPb) total brain activity power, and frontal alpha band asymmetry during rest and task performance were investigated.

RESULTS

No baseline differences were detected between the groups, except for education level. Active (but not Sham) ccPAS elevated the Stroop bias and the total brain activity power over the left LPFC while no stimulation-related influence was found on the LPPb or prefrontal brain asymmetry during task and the resting state. However, the stimulation-induced change in the Stroop bias was negatively correlated with the change in LPPb magnitude, positively correlated with changes in asymmetrical activity during the task, and negatively with left frontal alpha asymmetry during rest.

CONCLUSIONS

The ccPAS affected food-related emotional regulation, probably due to general reduction of inhibitory control during task performance. Further studies are needed to affirm the results with larger samples and to elucidate the development of beneficial ccPAS protocol for obesity with food addiction.

A full-factorial test of motivational and volitional intervention strategies for promoting exercise habit formation and exercise maintenance among new users of an online exercise class platform

Interventions often fail to achieve long-term behavioral maintenance. Utilizing motivational and volitional strategies to promote behavioral maintenance factors may improve this. Using a full-factorial experiment, we tested the effects of three intervention components (focused on intrinsic motivation and identity, exercise preparation habit, and exercise instigation habit) on exercise participation over a year, among new users (N = 751; 91% identifying as female, 54% identifying as White race) of a global, online exercise class platform, run by Les Mills International Ltd, called LM+. We also tested the intervention components' theoretical mechanisms of action-habit formation, intrinsic motivation, identity, and self-efficacy. Multi-level models found some support for a main effect of the exercise preparation habit intervention component in promoting self-reported and objective exercise participation (behavioral outcomes measured via monthly surveys and the LM+ platform; mechanisms measured via monthly surveys)-in particular online exercise class frequency (fixed effect estimate = 0.84, p < 0.05, and = 0.12, p < 0.05, respectively). The preparation habit component also significantly increased preparation habit strength (0.30, p < 0.05) and instigation habit strength (0.33, p < 0.05). Other expected effects were nonsignificant. Helping individuals form an exercise preparation habit may facilitate initiating and maintaining exercise over time, in particular for attending online exercise classes, potentially through promoting greater preparation and exercise instigation habit strength.

Long-Term Weight Loss Outcomes in a Virtual Weight Care Clinic Prescribing a Broad Range of Medications Alongside Behavior Change

Background

Virtually-delivered obesity care has the potential to increase access to weight loss interventions at scale. While there is ample literature assessing various weight loss interventions, studies specifically demonstrating outcomes of commercial programs offering antiobesity medications in virtual care settings are lacking.

Methods

This retrospective cohort study assessed the weight loss outcomes of 66,094 participants in a virtual weight care program that prescribes antiobesity medications alongside a digital behavior change program. Outcomes included the primary endpoint of percent weight loss at 12 months, as well as absolute change in body weight, change in body mass index (BMI), categorical weight loss at three, six, and 12 months, and stratifications by program engagement and medication type (first vs. second generation antiobesity medications).

Results

At program enrollment, members were on average 42.6 years old and 91.5% female, with a BMI of 36.0 kg/m2. At 12 months, the mean percent weight loss was 8.0%, with weight loss increasing over time from 2.9 kg (SD = 3.7, Cohen's d = 0.8) at 3 months, to 5.8 kg (SD = 6.1, Cohen's d = 0.9) at 6 months, to 8.0 kg (SD = 8.7, Cohen's d = 0.9) at 12 months (p < 0.001 for all time points). At 12 months, 64.2% had achieved ≥ 5% weight loss. Weight loss outcomes increased with program engagement. At 12 months, those engaging at least once weekly lost 10.0% of body weight, while those logging weight at least weekly lost 12.0%.

Conclusion

This study provides real-world evidence that users of a virtual commercial weight care clinic who were prescribed antiobesity medications achieved clinically significant weight loss at six and 12 months. These findings support the value of virtual platforms in efficiently scaling access to high-quality weight care.

GLP1Ra-based therapies and DXA-acquired musculoskeletal health outcomes: a focused meta-analysis of placebo-controlled trials

OBJECTIVE

The objective of this study was to evaluate the effect of glucagon-like peptide-1 receptor agonist (GLP1Ra)-based therapies on change in dual-energy x-ray absorptiometry (DXA)-acquired lean mass (LM) or bone mineral density (BMD).

METHODS

PubMed and Web of Science were searched from database inception through January 29, 2024, for randomized, placebo-controlled trials reporting on change in DXA-acquired LM or BMD measures associated with 12+ weeks of GLP1Ra-based treatment. Of 2618 articles, 9 trials met prespecified search criteria, with 7 reporting on change in total body LM and 2 reporting on change in BMD. For LM outcomes, a hierarchical Bayesian model was used to estimate treatment mean differences. BMD outcomes were described narratively.

RESULTS

LM was reported in a total of 659 participants (GLP1Ra-based therapies: n = 419; placebo: n = 240), with follow-up times ranging from mean (SD) 12 to 72 (33.5) weeks. At baseline, participants were aged mean (SD) 41.7 (7.6) years, and 75% were female, with BMI values ranging from 30 to 43 kg/m2. Compared with placebo, GLP1Ra-based treatment was associated with significantly reduced total body weight (-6.9 kg; 95% credible interval [CI]: -10.7 to -3.0). GLP1Ra-based treatment was also associated with significantly reduced LM (-1.9 kg; 95% CI: -3.5 to -0.2).

CONCLUSIONS

Approximately 30% of body weight lost with GLP1Ra-based therapy is LM. More data are needed assessing BMD outcomes.

Emotional Eating Interventions for Adults Living With Overweight and Obesity: A Systematic Review and Meta-Analysis of Behaviour Change Techniques

BACKGROUND

Emotional eating (EE) is a barrier to the long-term success of weight loss interventions. Psychological interventions targeting EE have been shown to reduce EE scores and weight (kg), though the mechanisms remain unclear. This review and meta-analysis aimed to identify the specific behaviour change techniques (BCTs) associated with improved outcomes.

METHODS

This is a review update and extension, with new studies extracted from searches of CINAHL, PsycINFO, MEDLINE and EMBASE 1 January 2022 to 31 April 2023. EE interventions for adults with BMI > 25 kg/m2 were considered for inclusion. Paper screening, extraction, BCT-coding and risk of bias were completed using the Template for Intervention Description and Replication (TIDieR) checklist, Behaviour Change Taxonomy v1 (BCTTv1) and Risk of Bias2 (RoB2)/Risk of Bias In Non-randomised Studies (ROBINS-I) tool. Narrative syntheses and random effects multi-level meta-analyses were conducted.

RESULTS

In total, 6729 participants were included across 47 studies (13 identified in the update). Forty-two studies contributed to the pooled estimate for the impact of interventions on EE (SMD = -0.99 [95% CI: -0.73 to -1.25], p < 0.001). Thirty-two studies contributed to the pooled estimate for the impact of interventions on weight (-4.09 kg [95% CI: -2.76 to -5.43 kg], p < 0.001). Five BCTs related to identity, values and self-regulation were associated with notable improvements to both weight and EE ('incompatible beliefs', 'goal setting outcome'. 'review outcome goals', 'feedback on behaviour' and 'pros/cons').

CONCLUSION

Implementation and evaluation of the highlighted BCTs are required. Weight management services should consider screening patients for EE to tailor interventions to individual needs.

Longer-term effects of intermittent fasting on body composition and cardiometabolic health in adults with overweight and obesity: A systematic review and meta-analysis

The aim of the present study was to investigate the effects of long-term intermittent fasting (IF) on body composition and cardiometabolic health in adults with overweight and obesity. PubMed, Web of Science, and Scopus were searched from inception to March 2024 to identify original randomized trials that investigated the effects of IF versus either a control diet (CON) and/or continuous caloric restriction (CR). Participants were adults with overweight and obesity and intervention durations were ≥ 6 months. Overall, a total of 24 studies involving 2032 participants were included in the meta-analysis. Compared with CON, IF significantly reduced body weight [WMD: -2.84 kg], BMI [WMD: -1.41 kg.m2], fat mass [WMD: -3.06 kg], fat-free mass [WMD: -0.81 kg], waist circumference [WMD: -3.85 cm], visceral fat [SMD: -0.37], fasting glucose [WMD: -0.14 mmol/l], triglycerides [WMD: -0.12 mmol/l], and diastolic blood pressure [WMD: -2.24 mmHg]. Conversely, IF significantly increased high-density lipoproteins [WMD: 0.04 mmol/l] when compared with CON, but had no effects on insulin, hemoglobin A1c%, total cholesterol, low-density lipoprotein, or systolic blood pressure. Compared with CR, IF significantly reduced fat mass [WMD: -0.70 kg], body fat percentage [WMD: -0.59%], and DBP [WMD: -0.91 mmHg], and increased HDL [WMD: 0.03 mmol/l], with no other significant effects. Subgroup analyses showed that the mode of IF and intervention duration were the primary moderators of IF effects on the markers. In adults with overweight or obesity, IF and CR are comparably effective for reducing body weight and adiposity, as well as for improving cardiometabolic health markers.

The prognostic role of food addiction for weight loss treatment outcomes in individuals with overweight and obesity: A systematic review and meta-analysis

Food addiction (FA) could be a potential prognostic factor of weight loss intervention outcomes. This systematic review with meta-analysis aimed to (1) estimate this prognostic effect of FA diagnosis and symptom count in individuals with overweight or obesity and (2) explore potential sources of heterogeneity based on properties of the weight loss intervention, study, and sample (e.g., age, gender, ethnicity). We searched PubMed, PsycINFO, and Web of Science for studies reporting on associations between pre-intervention FA (assessed with the Yale Food Addiction Scale) and weight outcomes after weight loss intervention in individuals with overweight or obesity without a medically diagnosed eating disorder. Twenty-five studies met inclusion criteria, including 4904 individuals (71% women, Mage = 41 years, BMI = 40.82 kg/m2), k = 18 correlations of weight loss with FA symptom count, and k = 21 mean differences between FA diagnosis groups. Pooled estimates of random-effects meta-analyses found limited support for a detrimental effect of FA symptom count and diagnosis on weight loss intervention outcomes. Negative associations with FA increased for behavioral weight loss interventions and among more ethnically diverse samples. More research on the interaction of FA with pre-existing mental health problems and environmental factors is needed.

The GIP receptor activates futile calcium cycling in white adipose tissue to increase energy expenditure and drive weight loss in mice

Obesity is a chronic disease that contributes to the development of insulin resistance, type 2 diabetes (T2D), and cardiovascular risk. Glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) and glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) co-agonism provide an improved therapeutic profile in individuals with T2D and obesity when compared with selective GLP-1R agonism. Although the metabolic benefits of GLP-1R agonism are established, whether GIPR activation impacts weight loss through peripheral mechanisms is yet to be fully defined. Here, we generated a mouse model of GIPR induction exclusively in the adipocyte. We show that GIPR induction in the fat cell protects mice from diet-induced obesity and triggers profound weight loss (∼35%) in an obese setting. Adipose GIPR further increases lipid oxidation, thermogenesis, and energy expenditure. Mechanistically, we demonstrate that GIPR induction activates SERCA-mediated futile calcium cycling in the adipocyte. GIPR activation further triggers a metabolic memory effect, which maintains weight loss after the transgene has been switched off, highlighting a unique aspect in adipocyte biology. Collectively, we present a mechanism of peripheral GIPR action in adipose tissue, which exerts beneficial metabolic effects on body weight and energy balance.

"It just made sense to me!" A Qualitative Exploration of Individual Motivation for Time-Restricted Eating

Time-Restricted Eating (TRE), a form of intermittent fasting, has gained popularity for weight control and metabolic health. It is not incorporated into dietary and clinical guidelines, and hence is generally not being recommended to the public. This qualitative study explores how individuals have discovered TRE as a form of dietary practice and their motivations for practising it. Using purposive and snowball sampling, we recruited 21 participants who had engaged in TRE for at least 3 months (range 3 months to over 5 years). In-depth interviews were conducted with an interview guide developed based on the Health Belief Model. We utilised an inductive coding process and thematic analysis to identify the factors motivating TRE adoption. Seven main themes emerged: (1) dissatisfaction and resistance to prior or traditional approaches, (2) perceived broader health benefits, (3) principles of TRE deemed logical, (4) low to no cost of adoption, (5) manageable psychosocial barriers, (6) being non-restrictive and easy to use, and (7) compatibility with personal lifestyle. This study provided insights into early phase of TRE adoption among individuals in real world settings. Future research should explore health practitioners' perspectives on TRE to better understand the acceptability and potential use of TRE as a weight management approach.

Identifying Factors Contributing to Dropouts in a Pilot Telenutrition Weight-Loss Program: A Qualitative Study

Background

Telehealth programs exhibit strong potential to improve health measures and quality of life among obese and overweight individuals for whom medical nutritional therapy remains a challenge due to poor adherence and dietary compliance. Supporting weight-management programs with dietary interventions or "telenutrition" and integrating telemonitoring and/or telehealth coaching have had a significant positive impact on weight-loss patients achieving their goals in long-term interventions.

Methods

The aim of the current study was to identify the factors leading patients to drop out of a telenutrition weight-loss program, including weekly telemonitoring (total of 36 weeks) and monthly telehealth coaching (total of 6 months). Descriptive qualitative semistructured interviews were held with 10 obese and overweight participants. The data gathered through these interviews were then thematically analyzed through a content analysis.

Results

The findings showed that 50% of participants who dropped out of the study felt pressured at work and/or university. Specifically, 60% reported being influenced by marital responsibilities, and 50% indicated that they did not achieve their goals. Nevertheless, participants who dropped out of the study reported that they were not negatively influenced by family factors and/or financial status. Participants also indicated feeling happy to take part in the program and noted that the diet positively influenced their psychological status. Participants also noted the clarity of instructions and that they were fully motivated during the trial.

Conclusions

The factors associated with dropouts in this study were different from those identified in the literature, given that our weight-loss program was delivered remotely and supported with weekly telemonitoring and monthly telehealth coaching. Despite the dropouts, the interview data highlighted positive factors that could enhance adherence to the dietary program and reduce dropout rates in larger and longer interventions. Future research should highlight the need to develop clear guidelines related to telenutrition programs or other digital health interventions to ensure successful long-term positive outcomes.

Deleterious Effects of Yoyo Dieting and Resistant Starch on Gastrointestinal Morphology

BACKGROUND

Obesity is associated with structural deterioration in the gut. Yoyo dieting, which refers to repeated phases of dieting and non-dieting periods leading to cyclic weight loss and regain, is a common occurrence in individuals with obesity. However, there is limited evidence on how gut structures are affected in yoyo dieting. There is good evidence suggesting that increased intake of resistant starch (RS) may be beneficial in promoting structural improvements in the gut. This investigation aimed to explore the effect of yoyo dieting on gastrointestinal structure and whether RS has beneficial effects in improving obesity-related gastrointestinal damage.

METHOD

In this study, male and female C57BL/6 mice were assigned to six different diets for 20 weeks: (1) control diet, (2) high fat diet (HF), (3) yoyo diet (alternating HF and control diets every 5 weeks), (4) control diet with RS, (5) HF with RS, and (6) yoyo diet with RS. Distal colon was collected for epithelial barrier integrity measurement. The small and large intestines were collected for histological assessment.

RESULTS

After 20 weeks, yoyo dieting resulted in increased colonic inflammation and exacerbated mucosal damage in comparison with continuous HF diet feeding. RS supplemented in HF and yoyo diets reduced mucosal damage in comparison to diets without RS. However, RS supplementation in a control diet significantly increased inflammation, crypt length, and goblet cell density. There were no significant differences in epithelial change and epithelial barrier integrity across diet groups.

CONCLUSIONS

This study suggests that yoyo dieting worsens gut damage, and incorporating high levels of RS may be detrimental in the absence of dietary challenge.

Loss of Sult1a1 reduces body weight and increases browning of white adipose tissue

Background and objective

Overweight and obesity affects millions of individuals worldwide and consequently represents a major public health concern. Individuals living with overweight and obesity have difficulty maintaining a low body weight due to known physiological mechanisms which prevent further weight loss and drive weight regain. In contrast, mechanisms which promote low body weight maintenance receive less attention and are largely unknown. To uncover these intrinsic mechanisms, we investigated a human cohort of constitutionally thin (CT) individuals which maintain a low body weight and are resistant to weight gain despite exposure to an obesogenic environment.

Methods

To identify novel genes that contribute to low body weight maintenance, we performed transcriptomics on adipose tissue biopsies collected from CT and normal body weight (NBW) individuals and identified sulfotransferase 1A1 (SULT1A1) as a target for further investigation in mice. Sult1a1 knockout (KO) mice were fed a standard diet to assess the impact of Sult1a1 deletion on metabolic traits. To determine if high-fat feeding recapitulated the CT weight gain resistance phenotype, Sult1a1 KO mice were fed a high-fat diet for 13-weeks. A subset of wild-type and Sult1a1 KO mice from the standard diet were further analyzed for characterization of adipose tissue respiratory capacity.

Results

In comparison to NBW controls, adipose tissue from CT individuals expresses less SULT1A1. Sult1a1 KO mice weigh 10% less at the end of the study period and on a high-fat diet, Sult1a1 KO mice tended to gain less weight and had reduced fat mass at 14-weeks of age. These changes were associated with reduced fasting insulin and lessened adipose tissue inflammation and fibrosis. Subcutaneous adipose tissue from Sult1a1 KO mice on a standard chow diet had elevated leak respiration, uncoupling protein 1 (UCP1) expression and increased expression of a mitochondrial marker, VDAC, associating Sult1a1 deletion to adipose tissue browning.

Conclusions

Our results associate Sult1a1 deletion with a tendency for lower body weight through remodeling of white adipose tissue towards a brown phenotype. The presence of UCP1, the expression of an additional mitochondrial protein and increased respiratory capacity suggest browning of the subcutaneous adipose tissue depot of Sult1a1 KO mice.

Mexican Clinical Practice Guidelines for Adult Overweight and Obesity Management

PURPOSE

To develop Mexico's first methodologically rigorous clinical practice guideline for the management of adult overweight and obesity. The target audiences are interdisciplinary healthcare professionals across healthcare systems who are the first point of contact for patients with obesity in Mexico, patients, and health system decision makers.

RECENT FINDINGS

A review of recent international obesity clinical practice guidelines and an expert consensus process identified: i) common recommendations appropriate for implementation in Mexico and ii) knowledge gaps requiring the formulation of new recommendations. In all, 20 new recommendations and 20 good practice statements were developed using the GRADE Evidence-to-Decision Framework and expert consensus. Overweight and obesity negatively impact the health and well-being of individuals and populations in Mexico. This guideline aims to establish a new evidence-based, patient-centered, non-stigmatizing, and practical treatment and management framework, based on the fundamental principles of chronic disease prevention and management.

Novel perspectives on the link between obesity and cancer risk: from mechanisms to clinical implications

Existing epidemiologic and clinical studies have demonstrated that obesity is associated with the risk of a variety of cancers. In recent years, an increasing number of experimental and clinical studies have unraveled the complex relationship between obesity and cancer risk and the underlying mechanisms. Obesity-induced abnormalities in immunity and biochemical metabolism, including chronic inflammation, hormonal disorders, dysregulation of adipokines, and microbial dysbiosis, may be important contributors to cancer development and progression. These contributors play different roles in cancer development and progression at different sites. Lifestyle changes, weight loss medications, and bariatric surgery are key approaches for weight-centered, obesity-related cancer prevention. Treatment of obesity-related inflammation and hormonal or metabolic dysregulation with medications has also shown promise in preventing obesity-related cancers. In this review, we summarize the mechanisms through which obesity affects the risk of cancer at different sites and explore intervention strategies for the prevention of obesity-associated cancers, concluding with unresolved questions and future directions regarding the link between obesity and cancer. The aim is to provide valuable theoretical foundations and insights for the in-depth exploration of the complex relationship between obesity and cancer risk and its clinical applications.

Multifrequency low-level laser-assisted lipolysis outcomes. A dataset from 101 patients

Obesity is a chronic and complex syndrome resulting from the interactions of genetic, environmental, metabolic, and psychological factors. This dataset collected clinical information from 101 patients with obesity who had undergone large-volume laser-assisted liposuction. Demographic, personal, and family history of disease were recorded, and weight and height were determined and subsequently used to calculate body mass index, % of total weight loss (%TWL), and % of excess body mass index loss (% EBMIL). Short-term incidence (<30 days) in post-operative complications was assessed according to the Clavien-Dindo System. The main outcomes analysed were the changes in body weight-related variables before and after the first three post-operative months and the incidence of early surgical complications. Due to the limited availability of structured, open-access datasets with information on traditional and laser-assisted lipolysis weight outcomes, this dataset is a valuable resource for researchers conducting comparative studies on liposuction procedures.

Semaglutide-induced weight loss improves mitochondrial energy efficiency in skeletal muscle

Objective

Glucagon-like peptide 1 receptor agonists (e.g. semaglutide) potently induce weight loss and thereby reducing obesity-related complications. However, weight regain occurs when treatment is discontinued. An increase in skeletal muscle oxidative phosphorylation (OXPHOS) efficiency upon diet-mediated weight loss has been described, which may contribute to reduced systemic energy expenditure and weight regain. We set out to determine the unknown effect of semaglutide on muscle OXPHOS efficiency.

Methods

C57BL/6J mice were fed a high-fat diet for 12 weeks before receiving semaglutide or vehicle for 1 or 3 weeks. The rate of ATP production and O2 consumption were measured by a high-resolution respirometry and fluorometry to determine OXPHOS efficiency in skeletal muscle at these 2 timepoints.

Results

Semaglutide treatment led to significant reductions in fat and lean mass. Semaglutide improved skeletal muscle OXPHOS efficiency, measured as ATP produced per O2 consumed (P/O) in permeabilized muscle fibers. Mitochondrial proteomic analysis revealed changes restricted to two proteins linked to complex III assembly (Lyrm7 and Ttc1, p <0.05 without multiple corrections) without substantial changes in the abundance of OXPHOS subunits.

Conclusions

These data indicate that weight loss with semaglutide treatment increases skeletal muscle mitochondrial efficiency. Future studies could test whether it contributes to weight regain.

Walking economy and exercise efficiency in successful weight loss maintainers

PURPOSE

Following short-term weight loss, the energetic cost of transport decreases and exercise efficiency increases. Whether changes persist during long-term weight maintenance is unknown.

METHODS

We compared walking economy and exercise efficiency in weight loss maintainers (WLM, maintaining ≥13.6 kg weight loss for ≥1 year), controls without obesity (NC, BMI similar to current BMI of WLM), and controls with overweight/obesity (OC, BMI similar to pre-weight loss BMI of WLM). Energy expenditure (EE) and respiratory quotient were measured using indirect calorimetry at rest, while standing, and during treadmill walking. Gross and net energetic cost of transport (J/kg/m) was measured during level treadmill walking at 0.75, 1.12, and 1.52 m/s. Gross, net, and delta efficiency (%) were measured during inclined treadmill walking (2 %, 4 %, and 6 % grade) and a constant speed (1.12 m/s).

RESULTS

WLM (n = 32, BMI: 23.8 ± 2.3 kg/m2) and NC (n = 28, BMI: 22.7 ± 1.6 kg/m2) had significantly lower EE (kJ/min) compared to OC (n = 26, BMI: 33.0 ± 4.5 kg/m2) during rest, standing, and walking (p < 0.01). Net energetic cost of transport was significantly lower in WLM compared to OC at 1.12 and 1.52 m/s (p < 0.05). Net efficiency was significantly greater in WLM compared to OC while walking (p ≤ 0.05). There were no significant differences between WLM and NC for any measures of economy or efficiency.

CONCLUSION

WLM had lower walking economy and greater walking efficiency compared to OC, but there were no differences between WLM and NC. Thus, individuals maintaining significant weight loss may be successful with long-term weight loss, in part, due to resistance against adaptive reductions in walking energetics.

Cardiometabolic characteristics of weight cycling: results from a mid-South regional comprehensive health care system

OBJECTIVE

The objective of this study was to determine the unique clinical and cardiometabolic risk characteristics of weight-cyclers and identify differences between weight-cyclers and individuals with other weight-change trajectories.

METHODS

A deidentified database of 1,428,204 Vanderbilt University Medical Center patients from 1997 to 2020 was included based on having ≥5 years of recorded weights. Patients with a history of malignant neoplasm, bariatric surgery, implausible BMI (e.g., <15 or >80 kg/m2), or missing documented height were excluded, yielding 83,261 participants categorized by weight trajectory, i.e., weight-stable, weight-gainer, weight-loser, or weight-cycler, based on criteria of ≥5% weight-change thresholds. Additionally, quartiles of average successive weight variability were evaluated to determine the effect of absolute differences among successive weight values.

RESULTS

Over half (55%) of participants were weight-cyclers, 23% were weight-gainers, 12% were weight-losers, and 10% were weight-stable over 5 years. Although baseline BMI did not differ among groups, weight-cyclers were more likely to have lower high-density lipoprotein cholesterol and higher blood glucose and triglyceride levels and to have been prescribed antihypertensive, dyslipidemia, and/or antidiabetic therapies. They were also younger and more likely to be smokers. Participants with the greatest weight variability (i.e., highest quartile of average successive weight variability) had higher cardiometabolic risk scores.

CONCLUSIONS

Weight cycling was highly prevalent but yielded no meaningful overall change in body weight after 5 years. These findings support a paradigm shift in weight management in individuals with overweight/obesity toward reducing cardiometabolic risk with or without weight loss.

Energy balance and obesity: the emerging role of glucagon like peptide-1 receptor agonists

PURPOSE OF REVIEW

With obesity affecting over one billion people globally, understanding and managing this complex condition is more crucial than ever. This review explores the emerging role of GLP-1 receptor agonists (GLP-1RA) in weight management, focusing on their impact on energy balance. It highlights the necessity of this investigation due to the limited knowledge on both the short-term and long-term implications of GLP-1RA on energy expenditure (EE) and energy intake (EI).

RECENT FINDINGS

GLP-1RA, such as liraglutide and semaglutide, have shown significant efficacy in promoting weight loss by reducing appetite, cravings and consequently, EI. Newer medications such as tirzepatide have demonstrated even greater weight loss success. Emerging evidence also suggests potential effects on EE, which could explain the greater weight loss success achieved with GLP-1 RA rather than typical lifestyle changes. However, comprehensive data on the total impact of these drugs on energy balance remain limited.

SUMMARY

The findings underscore the promising role of GLP-1RA in obesity management, particularly through mechanisms influencing both EI and EE. Future research should focus on systematically measuring all components of energy balance to fully elucidate the mechanisms of GLP-1RA and optimize their therapeutic use for personalized medicine.

Isomalto-Oligosaccharide Potentiates Alleviating Effects of Intermittent Fasting on Obesity-Related Cognitive Impairment during Weight Loss and the Rebound Weight Gain

Obesity-related cognitive dysfunction poses a significant threat to public health. The present study demonstrated mitigating effects of intermittent fasting (IF) and its combination with isomalto-oligosaccharides and IF (IF + IMO) on cognitive impairments induced by a high-fat-high-fructose (HFHF) diet in mice, with IF + IMO exhibiting superior effects. Transcriptomic analysis of the hippocampus revealed that the protective effects on cognition might be attributed to the suppression of toll-like receptor 4 (TLR4)/NFκB signaling, oxidative phosphorylation, and neuroinflammation. Moreover, both IF and IF + IMO modulated the gut microbiome and promoted the production of short-chain fatty acids, with IF + IMO displaying more pronounced effects. IF + IMO-modulated gut microbiota, metabolites, and molecular targets associated with cognitive impairments were further corroborated using human data from public databases Gmrepo and gutMgene. Furthermore, the fecal microbiome transplantation confirmed the direct impacts of IF + IMO-derived microbiota on improving cognition functions by suppressing TLR4/NFκB signaling and increasing BDNF levels. Notably, prior exposure to IF + IMO prevented weight-regain-induced cognitive decline, suppressed TLR4/NFκB signaling and inflammatory cytokines in the hippocampus, and mitigated weight regain-caused gut dysbacteriosis without altering body weight. Our study underscores that IMO-augmented alleviating effects of IF on obesity-related cognitive impairment particularly during weight-loss and weight-regain periods, presenting a novel nutritional strategy to tackle obesity-related neurodegenerative disorders.

Four-year follow-up of weight loss maintenance using electronic medical record data: The PROPEL trial

Rationale

Short-term weight loss is possible in a variety of settings. However, long-term, free-living weight loss maintenance following structured weight loss interventions remains elusive.

Objective

The purpose was to study body weight trajectories over 2 years of intensive lifestyle intervention (ILI) and up to 4 years of follow-up versus usual care (UC).

Methods

Data were obtained from electronic medical records (EMRs) from participating clinics. Baseline (Day 0) was established as the EMR data point closest but prior to the baseline date of the trial. The sample included 111 ILI and 196 UC patients. The primary statistical analysis focused on differentiating weight loss trajectories between ILI and UC.

Results

The ILI group experienced significantly greater weight loss compared with the UC group from Day 100 to Day 700, beyond which there were no significant differences. Intensive lifestyle intervention patients who maintained ≥5% and ≥10% weight loss at 24 months demonstrated significantly greater weight loss (p < 0.001) across the active intervention and follow-up.

Conclusions

Following 24 months of active intervention, patients with ILI regained weight toward their baseline to the point where ILI versus UC differences were no longer statistically or clinically significant. However, patients in the ILI who experienced ≥5% or ≥10% weight loss at the cessation of the active intervention maintained greater weight loss at the end of the follow-up phase.

Clinical Trial Registration

ClinicalTrials.gov: NCT02561221.

Pharmacotherapy of Weight-loss and Obesity with a Focus on GLP 1-Receptor Agonists

Obesity is a disease of epidemic proportions in the United States and contributes to morbidity and mortality for a large part of the population. In addition, the financial costs of this disease to society are high. Lifestyle modifications are key to prevention and treatment but adherence and long-term success have been challenging. Bariatric surgery has been available and pharmacologic approaches, first developed in the 1950s, continue to be an option; however, existing formulations have not provided optimal clinical efficacy and have had many concerning adverse effects. Over the last decade, glucagon-like peptide-1 (GLP-1) receptor agonists, a novel group of medications for the treatment of type 2 diabetes, were found to produce significant weight loss. Several formulations, at higher doses, received FDA approval for the treatment of obesity or those overweight with weight-related co-morbidities. More hormone-based therapies were and are being developed, some with dual or triple-receptor agonist activity. Their use, however, is not without questions and concerns as to long-term safety and efficacy, problems with cost and reimbursement, and how their use may intersect with public health efforts to manage the obesity epidemic. This review will focus on the GLP-1 receptor agonists currently used for weight loss and discuss their pharmacology, pertinent research findings establishing their benefits and risks, issues with prescribing these medications, and a perspective from a public health point of view.

Recommendations on the management of severe obesity in patients with inflammatory bowel disease of the Spanish Group on Crohn's Disease and Ulcerative Colitis (GETECCU), Spanish Society of Obesity (SEEDO), Spanish Association of Surgery (AEC) and Spanish Society of Digestive Endoscopy (SEED)

Obesity is a multifactorial, chronic, progressive and recurrent disease considered a public health issue worldwide and an important determinant of disability and death. In Spain, its current prevalence in the adult population is about 24% and an estimated prevalence in 2035 of 37%. Obesity increases the probability of several diseases linked to higher mortality such as diabetes, cardiovascular disease, hyperlipidemia, arterial hypertension, non-alcoholic fatty liver disease, several types of cancer, or obstructive sleep apnea. On the other hand, although the incidence of inflammatory bowel disease (IBD) is stabilizing in Western countries, its prevalence already exceeds 0.3%. Paralleling to general population, the current prevalence of obesity in adult patients with IBD is estimated at 15-40%. Obesity in patients with IBD could entail, in addition to its already known impact on disability and mortality, a worse evolution of the IBD itself and a worse response to treatments. The aim of this document, performed in collaboration by four scientific societies involved in the clinical care of severe obesity and IBD, is to establish clear and concise recommendations on the therapeutic possibilities of severe or typeIII obesity in patients with IBD. The document establishes general recommendations on dietary, pharmacological, endoscopic, and surgical treatment of severe obesity in patients with IBD, as well as pre- and post-treatment evaluation.

Utilization of antiobesity medications within the Military Health System

OBJECTIVE

The prevalence of overweight and obesity among beneficiaries of the Military Health System (MHS) is 41.6% and 30.5%, respectively. This incurs significant medical, fiscal, and military readiness costs. It is not currently known how the utilization of antiobesity medications (AOMs) within the MHS compares with that in the Veterans Health Administration or the private sector. Our aim was to assess the utilization of AOMs within the MHS.

METHODS

A cross-sectional study was conducted using data gathered from the MHS Data Repository and the inclusion of all adult TRICARE Prime and Plus beneficiaries ages 18 to 64 years who were prescribed at least one TRICARE-approved AOM during the years 2018 to 2022.

RESULTS

The total study population included 4,414,127 beneficiaries, of whom 1,871,780 were active-duty service members. The utilization of AOMs among the eligible population was 0.56% (0.44% among active-duty personnel). Liraglutide was the most-prescribed AOM (36% of the total). Female sex, age greater than or equal to 30 but less than 60 years, and enlisted or warrant officer rank were all associated with statistically significant higher odds of receiving AOMs.

CONCLUSIONS

Comparable with the US private sector, the MHS significantly underutilizes AOMs, including among active-duty service members, despite coverage of AOMs since 2018.

Efficacy, Safety, and Tolerability of a Very Low-Calorie Ketogenic Diet in Women with Obesity and Symptomatic Knee Osteoarthritis: A Pilot Interventional Study

BACKGROUND/OBJECTIVES

Obesity is a major risk factor for knee osteoarthritis (OA), and weight loss is crucial for its management. This pilot study explores the effects of a Very Low-Calorie Ketogenic Diet (VLCKD) in women with obesity and symptomatic knee OA.

METHODS

Women with symptomatic knee OA and obesity, defined as a body mass index (BMI) ≥ 30 kg/m2, were eligible for the VLCKD protocol. The intervention included a ketogenic phase from baseline (T0) to the 8th week (T8), followed by a progressive reintroduction of carbohydrates over the next 12 weeks, ending at the 20th week (T20). Body mass index (BMI), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the EuroQol 5D (EQ-5D), and the 36-item Short Form Health Survey (SF-36) were assessed at all time points. Generalized estimating equations were used to analyze the association between BMI and patient-reported outcomes across the study period.

RESULTS

Twenty participants started the study, but four discontinued the intervention, with two of these being due to adverse effects. The mean age of the 16 patients who completed the 20-week program was 57.3 ± 5.5 years, and their mean BMI was 40.0 ± 4.8 kg/m2. The mean BMI significantly decreased to 37.5 ± 4.5 at T4, 36.3 ± 4.6 at T8, and 34.8 ± 4.8 at T20 (all p < 0.001 compared to baseline). The total WOMAC score improved from a mean of 43.6 ± 16.9 at T0 to 30.2 ± 12.8 at T4 (p = 0.005) and further to 24.7 ± 10.6 at T8 (p = 0.001) and to 24.8 ± 15.9 at T20 (p = 0.005). The reduction in BMI was significantly correlated with the improvements in WOMAC, EQ-5D, and SF-36 over time. No major adverse effects were observed.

CONCLUSIONS

A 20-week VLCKD in women with obesity and knee OA significantly reduced their weight and improved their outcomes, warranting further research. This trial is registered with number NCT05848544 on ClinicalTrials.gov.

Yoyo Dieting, Post-Obesity Weight Loss, and Their Relationship with Gut Health

Excessive body weight is associated with many chronic metabolic diseases and weight loss, so far, remains the gold standard treatment. However, despite tremendous efforts exploring optimal treatments for obesity, many individuals find losing weight and maintaining a healthy body weight difficult. Weight loss is often not sustainable resulting in weight regain and subsequent efforts to lose weight. This cyclic pattern of weight loss and regain is termed "yoyo dieting" and predisposes individuals to obesity and metabolic comorbidities. How yoyo dieting might worsen obesity complications during the weight recurrence phase remains unclear. In particular, there is limited data on the role of the gut microbiome in yoyo dieting. Gut health distress, especially gut inflammation and microbiome perturbation, is strongly associated with metabolic dysfunction and disturbance of energy homeostasis in obesity. In this review, we summarise current evidence of the crosstalk between the gastrointestinal system and energy balance, and the effects of yoyo dieting on gut inflammation and gut microbiota reshaping. Finally, we focus on the potential effects of post-dieting weight loss in improving gut health and identify current knowledge gaps within the field, including gut-derived peptide hormones and their potential suitability as targets to combat weight regain, and how yoyo dieting and associated changes in the microbiome affect the gut barrier and the enteric nervous system, which largely remain to be determined.

The Impact of Yoyo Dieting and Resistant Starch on Weight Loss and Gut Microbiome in C57Bl/6 Mice

Cyclic weight loss and subsequent regain after dieting and non-dieting periods, a phenomenon termed yoyo dieting, places individuals at greater risk of metabolic complications and alters gut microbiome composition. Resistant starch (RS) improves gut health and systemic metabolism. This study aimed to investigate the effect of yoyo dieting and RS on the metabolism and gut microbiome. C57BL/6 mice were assigned to 6 diets for 20 weeks, including control, high fat (HF), yoyo (alternating HF and control diets every 5 weeks), control with RS, HF with RS, and yoyo with RS. Metabolic outcomes and microbiota profiling using 16S rRNA sequencing were examined. Yoyo dieting resulted in short-term weight loss, which led to improved liver health and insulin tolerance but also a greater rate of weight gain compared to continuous HF feeding, as well as a different microbiota profile that was in an intermediate configuration between the control and HF states. Mice fed HF and yoyo diets supplemented with RS gained less weight than those fed without RS. RS supplementation in yoyo mice appeared to shift the gut microbiota composition closer to the control state. In conclusion, yoyo dieting leads to obesity relapse, and increased RS intake reduces weight gain and might help prevent rapid weight regain via gut microbiome restoration.

Exercise and QUality Diet after Leukemia: A Randomized Weight Loss Trial among Adult Survivors of Childhood Leukemia in the Childhood Cancer Survivor Study

BACKGROUND

Obesity is prevalent in childhood cancer survivors and interacts with cancer treatments to potentiate risk for cardiovascular (CV) death. We tested a remote weight-loss intervention trial that was effective among adults with CV risk factors in a cohort of adult survivors of childhood acute lymphoblastic leukemia (ALL) with overweight/obesity.

METHODS

In this phase III efficacy trial, survivors of ALL enrolled in the Childhood Cancer Survivor Study with a body mass index ≥25 kg/m2 were randomized to a remotely delivered weight-loss intervention versus self-directed weight loss, stratified by history of cranial radiotherapy. The primary endpoint was the difference in weight loss at 24 months in an intent-to-treat analysis. Analyses were performed using linear mixed-effects models.

RESULTS

Among 358 survivors (59% female; median attained age: 37 years; IQR: 33-43 years), the baseline mean (SD) weight was 98.6 kg (24.0) for the intervention group (n = 181) and 94.9 kg (20.3) for controls (n = 177). Adherence to the intervention was poor; 15% of individuals in the intervention group completed 24/30 planned coaching calls. Weight at 24 months was available for 274 (77%) participants. After controlling for cranial radiotherapy, sex, race/ethnicity, and age, the mean (SE) change in weight from baseline to 24 months was -0.4 kg (0.8) for the intervention group and 0.2 kg (0.6) for control participants (P = 0.59).

CONCLUSIONS

A remote weight-loss intervention that was successful among adults with CV conditions did not result in significant weight loss among adult survivors of childhood ALL.

IMPACT

Future interventions in this population must be tailored to the unique needs of survivors to encourage engagement and adherence. See related In the Spotlight, p. 1147.

Nutritional considerations with antiobesity medications

The improved efficacy and generally favorable safety profile of recently approved and emerging antiobesity medications (AOMs), which result in an average weight reduction of ≥15%, represent significant advancement in the treatment of obesity. This narrative review aims to provide practical evidence-based recommendations for nutritional assessment, management, and monitoring of patients treated with AOMs. Prior to treatment, clinicians can identify preexisting nutritional risk factors and counsel their patients on recommended intakes of protein, dietary fiber, micronutrients, and fluids. During treatment with AOMs, ongoing monitoring can facilitate early recognition and management of gastrointestinal symptoms or inadequate nutrient or fluid intake. Attention should also be paid to other factors that can impact response to treatment and quality of life, such as physical activity and social and emotional health. In the context of treatment with AOMs, clinicians can play an active role in supporting their patients with obesity to improve their health and well-being and promote optimal nutritional and medical outcomes.

Weight Loss Programs: Why Do They Fail? A Multidimensional Approach for Obesity Management

PURPOSE OF REVIEW

Despite the prevalence of weight loss programs, their success rates remain discouraging, with around half of individuals regaining lost weight within two years. The primary objective of this review is to explore the factors contributing to the failure of weight loss programs and to provide insights into effective weight management strategies.

RECENT FINDINGS

Factors contributing to the failure of weight loss programs include the impracticality of restrictive diets, potential metabolic impacts, limited focus on lifestyle changes, genetic predispositions, psychological influences, socioeconomic status, and medical conditions. A holistic approach considering these factors is crucial for safe and sustainable weight loss. Key findings indicate the importance of holistic approaches to weight management, including lifestyle modifications, medical interventions, and behavioral and psychological strategies. Effective weight loss strategies emphasize low-calorie, nutrient-rich diets, regular physical activity, and interventions tailored to individual needs. Combining multiple approaches offers the best chance of successful weight management and improved health outcomes. This review provides insights into the complexities of obesity management and the factors contributing to the failure of weight loss programs. It highlights the necessity of adopting a holistic approach that addresses dietary habits, physical activity, genetic factors, psychological well-being, and socioeconomic influences. Recommendations include implementing lifestyle modifications, medical interventions when necessary, and integrating behavioral and psychological support to achieve sustainable weight loss and mitigate the global health challenge posed by obesity.