Quantification of the effect of energy imbalance on bodyweight

Effect of Replacing Sucrose in Beverages with Nonnutritive Sweetener Sucralose on Cardiometabolic Risk Factors Among Asian Indian Adults with Type 2 Diabetes: A 12-Week Randomized Controlled Trial

INTRODUCTION

Country-specific evidence-based research is crucial for understanding the role of nonnutritive sweeteners (NNS) in managing type 2 diabetes (T2D). The main aim of this study was to explore the effect of replacing sucrose with sucralose in coffee/tea in Asian Indians with type 2 diabetes (T2D).

METHODS

This 12-week, parallel-arm randomized controlled trial included 210 participants with T2D, assigned to the intervention group, where sugar/sucrose in coffee or tea was substituted with sucralose, or the control group, where sugar/sucrose was continued. Lifestyle factors remained unchanged. The primary outcome was change in HbA1c. Secondary outcomes were changes in body weight (BW), body mass index (BMI), waist circumference (WC), lipid profiles, and inflammatory markers.

RESULTS

At the end of 12 weeks, no change was observed in HbA1c, fasting plasma glucose, lipid profile, and inflammatory markers between or within groups. There was a small but significant reduction in BW (- 0.5 kg [95% CI - 1.0, - 0.1]; p = 0.02), BMI (- 0.2 kg/m2 [- 0.4, 0.0]; p = 0.03), and WC (- 0.8 cm [- 1.4, - 0.3]; p = 0.002) in the intervention group. Improvements were also observed in lipid accumulation product (p = 0.01), visceral adiposity index (p = 0.04), triglyceride/glucose index (p = 0.04), total energy intake (p = 0.04), and carbohydrate intake (p < 0.0001).

CONCLUSIONS

In Asian Indians with T2D, replacing about 60 kcal of added sucrose with sucralose in coffee/ tea had no benefit on glycemia but resulted in a small reduction in body weight, body mass index, and waist circumference.

TRIAL REGISTRATION

Clinical Trials Registry of India (CTRI/2021/04/032686).

Brain responses to intermittent fasting and the healthy living diet in older adults

Diet may promote brain health in metabolically impaired older individuals. In an 8-week randomized clinical trial involving 40 cognitively intact older adults with insulin resistance, we examined the effects of 5:2 intermittent fasting and the healthy living diet on brain health. Although intermittent fasting induced greater weight loss, the two diets had comparable effects in improving insulin signaling biomarkers in neuron-derived extracellular vesicles, decreasing the brain-age-gap estimate (reflecting the pace of biological aging of the brain) on magnetic resonance imaging, reducing brain glucose on magnetic resonance spectroscopy, and improving blood biomarkers of carbohydrate and lipid metabolism, with minimal changes in cerebrospinal fluid biomarkers for Alzheimer's disease. Intermittent fasting and healthy living improved executive function and memory, with intermittent fasting benefiting more certain cognitive measures. In exploratory analyses, sex, body mass index, and apolipoprotein E and SLC16A7 genotypes modulated diet effects. The study provides a blueprint for assessing brain effects of dietary interventions and motivates further research on intermittent fasting and continuous diets for brain health optimization. For further information, please see ClinicalTrials.gov registration: NCT02460783.

Derivation and validation of the Ottawa weight loss prediction model for patients on a low-calorie diet

Accurate weight predictions are essential for weight management program patients. The freely available National Institutes of Health Body Weight Planner (NIH-BWP) returns expected weights over time but overestimates weight when patients consume a low-calorie diet. This study sought to increase the accuracy of NIH-BWP predicted weights for people on low-calorie diets. People enrolled in a weight management program were included if they received meal replacements with defined caloric content for the 3 months of the weight loss phase of the program. The Ottawa Weight Loss Prediction Model (OWL-PM) modelled the relative difference between observed and NIH-BWP predicted weights using longitudinal analysis methods based on patient factors. OWL-PM was externally validated. 1761 people were included (mean age 46 years, 73.3% women) with a mean (SD) baseline weight in pounds and body mass index of 271.9 (55.6) and 43.9 (7.4), respectively. At the end of the program's weight loss phase, people lost a median (IQR) of 17.1% (14.8-19.5) of their baseline weight. Observed weight relative to NIH-BWP predicted weights had a median value of - 4.9% but ranged from - 32.1% to + 28.5%. After adjustment, weight overestimation by NIH-BWP was most pronounced in male patients, people without diabetes and with increased observation time. OWL-PM returned expected weights at 3 months that were significantly more accurate than those from NIH-BWP alone (mean difference observed vs. expected [95% CI] 6.7lbs [6.4-7.0] vs. 12.6lbs [12.1-13.0]). In the external validation cohort (n = 106), OWL-PM was significantly more accurate than NIH-BWP (mean squared error 24.3 vs. 40.0, p = 0.0018). OWL-PM incorporated patient-level covariates to significantly increase weight prediction accuracy of NIH-BWP in patients consuming a low-calorie diet.

Incretin hormones, obesity and gut microbiota

Over the past 40 years, the prevalence of obesity has risen dramatically, reaching epidemic proportions. By 2030 the number of people affected by obesity will reach 1.12 billion worldwide. Gastrointestinal hormones, namely incretins, play a vital role in the pathogenesis of obesity and its comorbidities. GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1), which are secreted from the intestine after nutrient intake and stimulate insulin secretion from pancreatic β cells, influence lipid metabolism, gastric empting, appetite and body weight. The gut microbiota plays an important role in various metabolic conditions, including obesity and type 2 diabetes and influences host metabolism through the interaction with enteroendocrine cells that modulate incretins secretion. Gut microbiota metabolites, such as short-chain fatty acids (SCFAs) and indole, directly stimulate the release of incretins from colonic enteroendocrine cells influencing host satiety and food intake. Moreover, bariatric surgery and incretin-based therapies are associated with increase gut bacterial richness and diversity. Understanding the role of incretins, gut microbiota, and their metabolites in regulating metabolic processes is crucial to develop effective strategies for the management of obesity and its associated comorbidities.

Association of both depressive symptoms scores and specific depressive symptoms with all-cause and cardiovascular disease mortality

BACKGROUND

The presence of depression related to an increased risk of all-cause and cardiovascular disease (CVD) mortality has been reported. However, studies conducted on certain specific depressive symptoms are scarce. Our purpose was to assess the effect of both depressive symptoms scores and certain specific depressive symptoms on all-cause and CVD mortality.

METHODS

In the present cohort study, all participants, aged 18 years or older, were enrolled in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2014. Depressive symptoms score was assessed using the validated 9-item Patient Health Questionnaire Depression Scale (PHQ-9), which ranges from 0 to 27, with a PHQ-9 score ≥ 10 diagnosed as depression. The outcome events were all-cause and CVD mortality, which were followed up from 2005 to 2014. The associations of both depressive symptoms score and certain specific depressive symptoms with all-cause and CVD mortality were examined by weighted multivariable proportional hazards models.

RESULTS

A total of 26,028 participants aged ≥ 18 years were included in the statistical analysis, including 12,813 (49.2%) males and 13,215 (50.8%) females, with a mean (SD) age of 47.34 (18.86) years. During the 9.32 (3.20) years of mean (SD) follow-up, 3261 deaths were recorded, of which 826 were cardiovascular deaths. All-cause mortality was 16.87/1000 person-years in subjects with depression. In terms of CVD mortality, these figures were 4.53/1000 person-years. In the full model (model 3), elevated depressive symptoms scores were independently associated with an increased risk of all-cause mortality (Highest depression symptom score group: adjusted hazard ratio, 1.63; 95% CI 1.44-1.85) and CVD mortality (Highest depression symptom score group: adjusted hazard ratio, 1.73; 95% CI 1.34-2.24). All 9 specific depressive symptoms that make up the PHQ-9 were related to an increased risk of all-cause mortality. However, only 3 symptoms, including trouble sleeping or sleeping too much, poor appetite or overeating, and suicidal ideation, were no significantly associated with an increased risk of CVD mortality.

CONCLUSIONS

The elevated depressive symptoms scores were strongly associated with an increased risk of all-cause and CVD mortality in US adults. Furthermore, all 9 specific depressive symptoms were associated with high all-cause mortality. However, trouble sleeping or sleeping too much, poor appetite or overeating, and suicidal ideation might not increase the risk of CVD mortality.

Estimated reduction in obesity prevalence and costs of a 20% and 30% ad valorem excise tax to sugar-sweetened beverages in Brazil: A modeling study

BACKGROUND

The consumption of sugar-sweetened beverages (SSBs) is associated with obesity, metabolic diseases, and incremental healthcare costs. Given their health consequences, the World Health Organization (WHO) recommended that countries implement taxes on SSB. Over the last 10 years, obesity prevalence has almost doubled in Brazil, yet, in 2016, the Brazilian government cut the existing federal SSB taxes to their current 4%. Since 2022, a bill to impose a 20% tax on SSB has been under discussion in the Brazilian Senate. To simulate the potential impact of increasing taxes on SSB in Brazil, we aimed to estimate the price-elasticity of SSB and the potential impact of a new 20% or 30% excise SSB tax on consumption, obesity prevalence, and cost savings.

METHODS AND FINDINGS

Using household purchases data from the Brazilian Household Budget Survey (POF) from 2017/2018, we estimated constant elasticity regressions. We used a log-log specification by income level for all beverage categories: (1) sugar-sweetened beverages; (2) alcoholic beverages; (3) unsweetened beverages; and (4) low-calorie or artificially sweetened beverages. We estimated the adult nationwide baseline intake for each beverage category using 24-h dietary recall data collected in 2017/2018. Taking group one as the taxed beverages, we applied the price and cross-price elasticities to the baseline intake data, we obtained changes in caloric intake. The caloric reduction was introduced into an individual dynamic model to estimate changes in weight and obesity prevalence. No benefits on cost savings were modeled during the first 3 years of intervention to account for the time lag in obesity cases to reduce costs. We multiplied the reduction in obesity cases during 7 years by the obesity costs per capita to predict the costs savings attributable to the sweetened beverage tax. SSB price elasticities were higher among the lowest tertile of income (-1.24) than in the highest income tertile (-1.13), and cross-price elasticities suggest SSB were weakly substituted by milk, water, and 100% fruit juices. We estimated a caloric change of -17.3 kcal/day/person under a 20% excise tax and -25.9 kcal/day/person under a 30% tax. Ten years after implementation, a 20% tax is expected to reduce obesity prevalence by 6.7%; 9.1% for a 30% tax. These reductions translate into a -2.8 million and -3.8 million obesity cases for a 20% and 30% tax, respectively, and a reduction of $US 13.3 billion and $US 17.9 billion in obesity costs over 10 years for a 20% and 30% tax, respectively. Study limitations include using a quantile distribution method to adjust self-reported baseline weight and height, which could be insufficient to correct for reporting bias; also, weight, height, and physical activity were assumed to be steady over time.

CONCLUSIONS

Adding a 20% to 30% excise tax on top of Brazil's current federal tax could help to reduce the consumption of ultra-processed beverages, empty calories, and body weight while avoiding large health-related costs. Given the recent cuts to SSB taxes in Brazil, a program to revise and implement excise taxes could prove beneficial for the Brazilian population.

Reliability and Validity of a Theory-Based Determinants of Eating and Physical Activity Behaviors Questionnaire for Chinese Elementary School Children

OBJECTIVE

The primary objective of this study was to develop and validate a Social Cognitive Theory-based instrument to identify psychosocial factors that influence diet and physical activity among Chinese children aged 10-12 years.

DESIGN

This is a cross-sectional study, with data collected from questionnaires.

SETTING

Two elementary schools in Beijing, China.

PARTICIPANTS

Fourth to sixth-grade students (N = 1,486) aged 10-12 years were recruited.

VARIABLES MEASURED

Gender, height, weight, nation, and grade were collected. Energy-balanced eating behaviors and their related sociopsychological factors were surveyed.

ANALYSIS

Confirmatory factor analysis, Pearson correlations, Cronbach α index, and mediation analysis were used.

RESULTS

(1) Confirmatory factor analysis revealed a 6-factor solution (51 items) and all factor loadings > 0.32, indicating that the model fitness was acceptable. (2) All correlation coefficients are statistically significant. All of the Cronbach α indexes were > 0.65, indicating acceptable reliability. (3) The mediating effect of goal intention and outcome expectations between self-efficacy and habit strength was statistically significant (P < 0.01), verifying the theory structure.

CONCLUSIONS AND IMPLICATIONS

This questionnaire exhibits good internal consistency, reliability, and structural validity. It can be effectively employed to investigate energy-balanced eating behaviors related to the Social Cognitive Theory in Chinese children.

Modelling impacts of a salt and sugar tax on hypothetical intra-category food substitutions, BMI and environmental footprints in the UK population

PURPOSE

Taxes on unhealthy foods can help improve population health in the United Kingdom (UK), but the health effects of food substitutions resulting from these taxes are often unclear. We investigated the potential impacts of a salt and sugar tax on hypothetical intra-category food substitutions, cost, body-mass index (BMI), and environmental footprints.

METHODS

Purchase panel data from Kantar (2017) were used to determine the most popular foods high in salt or sugar within eight 'salt-intensive'/'sugar-intensive' food categories. Within food categories, the most popular lower salt (≤ 1.5 g salt/100 g product) and lower sugar (≤ 22.5 g sugar/100 g product) substitutes were also identified. Hypothetical swaps between high salt/sugar foods and lower salt/sugar substitutes were explored, focusing on changes to cost, caloric intake and BMI, and environmental impacts in the UK population.

RESULTS

The suggested intra-category substitutions were largely like-for-like and did not accrue an added overall cost to consumers. The substitutions reduced calorie intake by about 200 kcal/day and lowered the prevalence of overweight and obesity in the UK from approximately 60-65% to about 40-45%. The proposed food substitutions led to a total reduction of -2.7Mt of greenhouse gases, ∼ -500.000 ha of land, -0.5km3 of blue water, -12km3 of scarcity weighted water, ∼ -12.000t of phosphorus, and nearly - 14.000t of sulphur dioxide over one year for the UK population due to reductions in calorie intake.

CONCLUSION

Food substitutions following a tax on salt and sugar could lead to significant benefits for health and the environment, without necessarily resulting in major changes to people's expenditure on familiar salty and sugary snacks.

Quantification of the effect of GLP-1R agonists on body weight using in vitro efficacy information: An extension of the Hall body composition model

Obesity has become a major public health concern worldwide. Pharmacological interventions with the glucagon-like peptide-1 receptor agonists (GLP-1RAs) have shown promising results in facilitating weight loss and improving metabolic outcomes in individuals with obesity. Quantifying drug effects of GLP-1RAs on energy intake (EI) and body weight (BW) using a QSP modeling approach can further increase the mechanistic understanding of these effects, and support obesity drug development. An extensive literature-based dataset was created, including data from several diet, liraglutide and semaglutide studies and their effects on BW and related parameters. The Hall body composition model was used to quantify and predict effects on EI. The model was extended with (1) a lifestyle change/placebo effect on EI, (2) a weight loss effect on activity for the studies that included weight management support, and (3) a GLP-1R agonistic effect using in vitro potency efficacy information. The estimated reduction in EI of clinically relevant dosages of semaglutide (2.4 mg) and liraglutide (3.0 mg) was 34.5% and 13.0%, respectively. The model adequately described the resulting change in BW over time. At 20 weeks the change in BW was estimated to be -17% for 2.4 mg semaglutide and -8% for 3 mg liraglutide, respectively. External validation showed the model was able to predict the effect of semaglutide on BW in the STEP 1 study. The GLP-1RA body composition model can be used to quantify and predict the effect of novel GLP-1R agonists on BW and changes in underlying processes using early in vitro efficacy information.

A unified framework for prediction of liver steatosis dynamics in response to different diet and drug interventions

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disorder, characterized by the accumulation of excess fat in the liver, and is a driving factor for various severe liver diseases. These multi-factorial and multi-timescale changes are observed in different clinical studies, but these studies have not been integrated into a unified framework. In this study, we aim to present such a unified framework in the form of a dynamic mathematical model.

METHODS

For model training and validation, we collected data for dietary or drug-induced interventions aimed at reducing or increasing liver fat. The model was formulated using ordinary differential equations (ODEs) and the mathematical analysis, model simulation, model formulation and the model parameter estimation were all performed in MATLAB.

RESULTS

Our mathematical model describes accumulation of fat in the liver and predicts changes in lipid fluxes induced by both dietary and drug interventions. The model is validated using data from a wide range of drug and dietary intervention studies and can predict both short-term (days) and long-term (weeks) changes in liver fat. Importantly, the model computes the contribution of each individual lipid flux to the total liver fat dynamics. Furthermore, the model can be combined with an established bodyweight model, to simulate even longer scenarios (years), also including the effects of insulin resistance and body weight. To help prepare for corresponding eHealth applications, we also present a way to visualize the simulated changes, using dynamically changing lipid droplets, seen in images of liver biopsies.

CONCLUSION

In conclusion, we believe that the minimal model presented herein might be a useful tool for future applications, and to further integrate and understand data regarding changes in dietary and drug induced changes in ectopic TAG in the liver. With further development and validation, the minimal model could be used as a disease progression model for steatosis.

The association between gut microbiota and resting metabolic rate in overweight/obese women: a case-control study

Purpose

When examining the underlying processes of obesity, evaluation of gut flora and energy homeostasis can be crucial since disruption of the normal gut microbiota community and energy imbalances are significant factors in the development of obesity. Therefore, this study aimed to compare the relative abundance of important obesity modulator gut microbiota (including Firmicutes, Bacteroidetes, Bifidobactrium spp., Lactobacillus spp., Bacteroides fragilis, Faecalibacterium prausnitzii, Akkermansia muciniphila, and Escherichia coli) in fecal samples of normometabilic and hypometabolic overweight/obese individuals.

Methods

This matched case-control study conducted on 36 healthy women aged 18-50 years old. An indirect calorimeter and impedance body analyzer were used to assess resting metabolic rate (RMR) and body composition, respectively. Dietary intake and physical activity were assessed using questionnaires. To determine the abundance of the abovementioned gut microbiota, quantitative polymerase chain reaction (qPCR) method was performed. Moreover, ELISA kits were used to assess leptin, ghrelin, and insulin hormones.

Results

The results highlighted higher load of Firmicutes (p = 0.02), F. prausnitzii (p < 0.001), and B. fragilis (p = 0.02) in the normometabolic individuals compared to the hypometabolic ones. Besides, the positive correlation between the abundance of Firmicutes (β = 7.76 × 10-1, p = 0.01), F. prausnitzii (β = 1.29 × 10-5, p = 0.01), and B. fragilis (β = 4.13 × 10-6, p = 0.04) with the RMR have been shown. Whereas the abundance of Bacteroidetes, A. muciniphila, Lactobacillus spp., Bifidobactrium spp., and E. coli showed no significant difference (p > 0.05) and no significant correlation with the RMR except Lactobacillus spp. (β = 1.73 × 10-4, p = 0.01).

Conclusion

It seems that gut microbiota can be a potential target for refining host energy homeostasis and treating obesity and its consequences.

Physiology of the weight-loss plateau in response to diet restriction, GLP-1 receptor agonism, and bariatric surgery

OBJECTIVE

The objective of this study was to investigate why different weight-loss interventions result in varying durations of weight loss prior to approaching plateaus.

METHODS

A validated mathematical model of energy metabolism and body composition dynamics was used to simulate mean weight- and fat-loss trajectories in response to diet restriction, semaglutide 2.4 mg, tirzepatide 10 mg, and Roux-en-Y gastric bypass (RYGB) surgery interventions. Each intervention was simulated by adjusting two model parameters affecting energy intake to fit the mean weight-loss data. One parameter represented the persistent shift of the system from baseline equilibrium, and the other parameter represented the strength of the feedback control circuit relating weight loss to increased appetite.

RESULTS

RYGB surgery resulted in a persistent intervention magnitude more than threefold greater than diet restriction and about double that of tirzepatide and semaglutide. All interventions except diet restriction substantially weakened the appetite feedback control circuit, resulting in an extended period of weight loss prior to the plateau.

CONCLUSIONS

These preliminary mathematical modeling results suggest that both glucagon-like peptide 1 (GLP-1) receptor agonism and RYGB surgery interventions act to weaken the appetite feedback control circuit that regulates body weight and induce greater persistent effects to shift the body weight equilibrium compared with diet restriction.

Economic Evaluations of Obesity-Targeted Sugar-Sweetened Beverage (SSB) Taxes-A Review to Identify Methodological Issues

INTRODUCTION

Economic evaluations of public health interventions like sugar-sweetened beverage (SSB) taxes face difficulties similar to those previously identified in other public health areas. This stems from challenges in accurately attributing effects, capturing outcomes and costs beyond health, and integrating equity effects. This review examines how these challenges were addressed in economic evaluations of SSB taxes.

METHODS

A systematic review was conducted to identify economic evaluations of SSB taxes focused on addressing obesity in adults, published up to February 2021. The methodological challenges examined include measuring effects, valuing outcomes, assessing costs, and incorporating equity.

RESULTS

Fourteen economic evaluations of SSB taxes were identified. Across these evaluations, estimating SSB tax effects was uncertain due to a reliance on indirect evidence that was less robust than evidence from randomised controlled trials. Health outcomes, like quality-adjusted life years, along with a healthcare system perspective for costs, dominated the evaluations of SSB taxes, with a limited focus on broader non-health consequences. Equity analyses were common but employed significantly different approaches and exhibited varying degrees of quality.

CONCLUSION

Addressing the methodological challenges remains an issue for economic evaluations of public health interventions like SSB taxes, suggesting the need for increased attention on those issues in future studies. Dedicated methodological guidelines, in particular addressing the measurement of effect and incorporation of equity impacts, are warranted.

Effect of an eight-week high-intensity interval training programme on circulating sphingolipid levels in middle-aged adults at elevated cardiometabolic risk (SphingoFIT)-Protocol for a randomised controlled exercise trial

INTRODUCTION

Evidence indicates that sphingolipid accumulation drives complex molecular alterations promoting cardiometabolic diseases. Clinically, it was shown that sphingolipids predict cardiometabolic risk independently of and beyond traditional biomarkers such as low-density lipoprotein cholesterol. To date, little is known about therapeutic modalities to lower sphingolipid levels. Exercise, a powerful means to prevent and treat cardiometabolic diseases, is a promising modality to mitigate sphingolipid levels in a cost-effective, safe, and patient-empowering manner.

METHODS

This randomised controlled trial will explore whether and to what extent an 8-week fitness-enhancing training programme can lower serum sphingolipid levels of middle-aged adults at elevated cardiometabolic risk (n = 98, 50% females). The exercise intervention will consist of supervised high-intensity interval training (three sessions weekly), while the control group will receive physical activity counselling based on current guidelines. Blood will be sampled early in the morning in a fasted state before and after the 8-week programme. Participants will be provided with individualised, pre-packaged meals for the two days preceding blood sampling to minimise potential confounding. An 'omic-scale sphingolipid profiling, using high-coverage reversed-phase liquid chromatography coupled to tandem mass spectrometry, will be applied to capture the circulating sphingolipidome. Maximal cardiopulmonary exercise tests will be performed before and after the 8-week programme to assess patient fitness changes. Cholesterol, triglycerides, glycated haemoglobin, the homeostatic model assessment for insulin resistance, static retinal vessel analysis, flow-mediated dilatation, and strain analysis of the heart cavities will also be assessed pre- and post-intervention. This study shall inform whether and to what extent exercise can be used as an evidence-based treatment to lower circulating sphingolipid levels.

TRIAL REGISTRATION

The trial was registered on www.clinicaltrials.gov (NCT06024291) on August 28, 2023.

Predicted impact of banning nonessential, energy-dense food and beverages in schools in Mexico: A microsimulation study

BACKGROUND

Childhood obesity is a growing concern worldwide. School-based interventions have been proposed as effective means to improve nutritional knowledge and prevent obesity. In 2023, Mexico approved a reform to the General Education Law to strengthen the ban of sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools and surroundings. We aimed to predict the expected one-year change in total caloric intake and obesity prevalence by introducing the ban of NEDFBs sales in schools, among school-aged children and adolescents (6 to 17 years old) in Mexico.

METHODS AND FINDINGS

We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and then estimated total energy intake (TEI) per day. The TEI after the intervention was estimated under 4 scenarios: (1) using national data to inform the intervention effect; (2) varying law compliance; (3) using meta-analytic data to inform the intervention effect size on calories; and (4) using national data to inform the intervention effect by sex and socioeconomic status (SES). We used Hall's microsimulation model to estimate the potential impact on body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools. We found that children could reduce their daily energy intake by 33 kcal/day/person (uncertainty interval, UI, [25, 42] kcal/day/person), reducing on average 0.8 kg/person (UI [0.6, 1.0] kg/person) and 1.5 percentage points (pp) in obesity (UI [1.1, 1.9] pp) 1 year after implementing the law. We showed that compliance will be key to the success of this intervention: considering a 50% compliance the intervention effect could reduce 0.4 kg/person (UI [0.3, 0.5] kg/person). Our sensitivity analysis showed that the ban could reduce body weight by 1.3 kg/person (UI [0.8, 1.8] kg/person) and up to 5.4 kg/person (UI [3.4, 7.5] kg/person) in the best-case scenario. Study limitations include assuming that obesity and the contribution of NEDFBs consumed at school remain constant over time, assuming full compliance, and not considering the potential effect of banning NEDFBs in stores near schools.

CONCLUSIONS

Even in the most conservative scenario, banning sales of NEDFBs in schools is expected to significantly reduce obesity, but achieving high compliance will be key to its success.

WHY WAS THIS STUDY DONE?

- School-based interventions have been recognized as effective means to improve nutritional knowledge and prevent obesity-related diseases.- In December 2023, the Chamber of Representatives of Mexico approved an amendment that strengthens and updates the General Education Law (Article 75) and nutritional guidelines to ban the sales and advertising of nonessential energy-dense food and beverages (NEDFBs) in schools.

WHAT DID THE RESEARCHERS DO AND FIND?

- We used age-specific equations to predict baseline fat-free mass (FFM) and fat mass (FM) and total energy intake (TEI) per day.- We used microsimulation modeling to predict body weight and obesity prevalence of children and adolescents 1 year after implementing the intervention in Mexican schools.- Our modeling study suggests that an important impact on obesity prevalence can be expected if the law is implemented and enforced as intended.

WHAT DO THESE FINDINGS MEAN?

- If successful, this law could serve as an example beyond Mexico on how to achieve changes in body weight through school food regulation.- An important limitation of our main scenario is that we assumed full compliance of schools with the law, yet lower compliance will reduce its impact. We also did not consider historical trends on obesity or NEDFBs consumed in schools during our 1 year simulation, and we considered only the ban impact inside schools, excluding effects near and outside schools.

Switching diets after 6-months does not result in renewed weight loss: a secondary analysis of a 12-month crossover randomized trial

Weight change trajectory from diet and lifestyle interventions typically involves rapid weight loss followed by a weight plateau after approximately 6 months. Changing from one weight-loss diet to another at the time of the plateau could instigate renewed weight loss. Therefore, our secondary analysis aimed to assess trajectory of weight loss in a 12-month, randomized, cross-over study. Forty-two adults were randomized to eat a healthy low-fat or healthy low-carbohydrate diet for 6 months then switched to the opposite diet for an additional 6 months. Regardless of diet assignment, participants experienced rapid initial weight loss, which slowed between 3 to 6 months. After switching diets at 6 months, weight modestly decreased until 9 months, but at a rate slower than the initial 3 months and slower than the rate from 3 to 6 months. This suggests that the weight loss plateau typically seen at 6 months is physiological and cannot be overcome by simply switching to a different weight-loss diet.

What could be the reasons for not losing weight even after following a weight loss program?

INTRODUCTION

Approximately four million people worldwide die annually because of obesity. Weight loss is commonly recommended as a first-line therapy in overweight and obese patients. Although many individuals attempt to lose weight, not everyone achieves optimal success. Few studies point out that weight loss eventually slows down, stagnates or reverses in 85% of the cases.

RESEARCH QUESTION

What could be the reasons for not losing weight even after following a weight loss program?

METHODS

A scoping review of the literature was performed using weight loss-related search terms such as 'Obesity,' 'Overweight,' 'Lifestyle,' 'weight loss,' 'Basal Metabolism,' 'physical activity,' 'adherence,' 'energy balance,' 'Sleep' and 'adaptations. The search involved reference tracking and database and web searches (PUBMED, Science Direct, Elsevier, Web of Science and Google Scholar). Original articles and review papers on weight loss involving human participants and adults aged > 18 years were selected. Approximately 231 articles were reviewed, and 185 were included based on the inclusion criteria.

DESIGN

Scoping review.

RESULTS

In this review, the factors associated with not losing weight have broadly been divided into five categories. Studies highlighting each subfactor were critically reviewed and discussed. A wide degree of interindividual variability in weight loss is common in studies even after controlling for variables such as adherence, sex, physical activity and baseline weight. In addition to these variables, variations in factors such as previous weight loss attempts, sleep habits, meal timings and medications can play a crucial role in upregulating or downregulating the association between energy deficit and weight loss results.

CONCLUSION

This review identifies and clarifies the role of several factors that may hinder weight loss after the exploration of existing evidence. Judging the effectiveness of respective lifestyle interventions by simply observing the 'general behavior of the groups' is not always applicable in clinical practice. Each individual must be monitored and advised as per their requirements and challenges.

Gastric mechanosensitive channel Piezo1 regulates ghrelin production and food intake

Ghrelin, produced mainly by gastric X/A-like cells, triggers a hunger signal to the central nervous system to stimulate appetite. It remains unclear whether X/A-like cells sense gastric distention and thus regulate ghrelin production. Here we show that PIEZO1 expression in X/A-like cells decreases in patients with obesity when compared to controls, whereas it increases after sleeve gastrectomy. Male and female mice with specific loss of Piezo1 in X/A-like cells exhibit hyperghrelinaemia and hyperphagia and are more susceptible to overweight. These phenotypes are associated with impairment of the gastric CaMKKII/CaMKIV-mTOR signalling pathway. Activation of PIEZO1 by Yoda1 or gastric bead implantation inhibits ghrelin production, decreases energy intake and induces weight loss in mice. Inhibition of ghrelin production by Piezo1 through the CaMKKII/CaMKIV-mTOR pathway can be recapitulated in a ghrelin-producing cell line mHypoE-42. Our study reveals a mechanical regulation of ghrelin production and appetite by PIEZO1 of X/A-like cells, which suggests a promising target for anti-obesity therapy.

Effect of calorie labelling in the out-of-home food sector on adult obesity prevalence, cardiovascular mortality, and social inequalities in England: a modelling study

BACKGROUND

England implemented a menu calorie labelling policy in large, out-of-home food businesses in 2022. We aimed to model the likely policy impact on population-level obesity and cardiovascular disease mortality, as well as the socioeconomic equity of estimated effects, in the adult population in England.

METHODS

For this modelling analysis, we built a comparative assessment model using two scenarios: the current implementation scenario refers to actual deployment only in large (≥250 employees), out-of-home food businesses, whereas the full implementation scenario refers to deployment in every out-of-home food business. We compared each scenario with a counterfactual: the scenario in which no intervention is implemented (ie, baseline). For both scenarios, we modelled the impact of the policy through assumed changes in energy intake due to either consumer response or product reformulation by retailers. We used data from the Office for National Statistics and the National Diet and Nutrition Survey 2009-19, and modelled the effect over 20 years (ie, 2022-41) to capture the long-term impact of the policy and provided mid-period results after 10 years. We used the Monte Carlo approach (2500 iterations) to estimate the uncertainty of model parameters. For each scenario, the model generated the change in obesity prevalence and the total number of deaths prevented or postponed.

FINDINGS

The current implementation scenario was estimated to reduce obesity prevalence by 0·31 percentage points (absolute; 95% uncertainty interval [UI] 0·10-0·35), which would prevent or postpone 730 cardiovascular disease deaths (UI 430-1300) of the 830 000 deaths (UI 600 000-1 200 000) expected over 20 years. However, the health benefits would be increased if calorie labelling was implemented in all out-of-home food businesses (2·65 percentage points reduction in obesity prevalence [UI 1·97-3·24] and 9200 cardiovascular disease deaths prevented or postponed [UI 5500-16 000]). Results were similar in the most and the least deprived socioeconomic groups.

INTERPRETATION

This study offers the first modelled estimation of the impact of the menu calorie labelling regulation on the adult population in England, although we did not include a cost-effectiveness analysis. Calorie labelling might result in a reduction in obesity prevalence and cardiovascular disease mortality without widening health inequalities. However, our results emphasise the need for the government to be more ambitious by applying this policy to all out-of-home food businesses to maximise impact.

FUNDING

European Research Council.

Impact of the UK soft drinks industry levy on health and health inequalities in children and adolescents in England: An interrupted time series analysis and population health modelling study

BACKGROUND

The soft drinks industry levy (SDIL) in the United Kingdom has led to a significant reduction in household purchasing of sugar in drinks. In this study, we examined the potential medium- and long-term implications for health and health inequalities among children and adolescents in England.

METHODS AND FINDINGS

We conducted a controlled interrupted time series analysis to measure the effects of the SDIL on the amount of sugar per household per week from soft drinks purchased, 19 months post implementation and by index of multiple deprivation (IMD) quintile in England. We modelled the effect of observed sugar reduction on body mass index (BMI), dental caries, and quality-adjusted life years (QALYs) in children and adolescents (0 to 17 years) by IMD quintile over the first 10 years following announcement (March 2016) and implementation (April 2018) of the SDIL. Using a lifetable model, we simulated the potential long-term impact of these changes on life expectancy for the current birth cohort and, using regression models with results from the IMD-specific lifetable models, we calculated the impact of the SDIL on the slope index of inequality (SII) in life expectancy. The SDIL was found to have reduced sugar from purchased drinks in England by 15 g/household/week (95% confidence interval: -10.3 to -19.7). The model predicts these reductions in sugar will lead to 3,600 (95% uncertainty interval: 946 to 6,330) fewer dental caries and 64,100 (54,400 to 73,400) fewer children and adolescents classified as overweight or obese, in the first 10 years after implementation. The changes in sugar purchasing and predicted impacts on health are largest for children and adolescents in the most deprived areas (Q1: 11,000 QALYs [8,370 to 14,100] and Q2: 7,760 QALYs [5,730 to 9,970]), while children and adolescents in less deprived areas will likely experience much smaller simulated effects (Q3: -1,830 QALYs [-3,260 to -501], Q4: 652 QALYs [-336 to 1,680], Q5: 1,860 QALYs [929 to 2,890]). If the simulated effects of the SDIL are sustained over the life course, it is predicted there will be a small but significant reduction in slope index of inequality: 0.76% (95% uncertainty interval: -0.9 to -0.62) for females and 0.94% (-1.1 to -0.76) for males.

CONCLUSIONS

We predict that the SDIL will lead to medium-term reductions in dental caries and overweight/obesity, and long-term improvements in life expectancy, with the greatest benefits projected for children and adolescents from more deprived areas. This study provides evidence that the SDIL could narrow health inequalities for children and adolescents in England.

Ten weeks of low-volume walking training improve cardiometabolic health and body composition in sedentary postmenopausal women with obesity without affecting markers of bone metabolism

This study aimed to determine the effects of walking exercise to induce a mild energy deficit and to improve body composition and metabolic status in postmenopausal women (PMW) with obesity as means of minimizing endocrine disruption and maintaining bone health. Twenty-four PMW with obesity (age: 55.0 ± 3.7 y, BMI: 32.9 ± 4.2 kg/m2, percent body fat: 46.2 ± 3.6%) were randomly assigned into either exercise (n = 12) or control (n = 12) groups. Exercise group participated in a-10 week supervised progressive walking programme   and control group maintained regular habits. Pre- and post-training assessments included body composition, bone mass, peak oxygen uptake (V ˙ O2peak), osteocalcin, bone alkaline phosphatase (BAP), type I collagen cross-linked C-telopeptide (CTX)glucose, glycated haemoglobin (HbA1c)), leptin and adiponectin. Results: Following the training program, body weight (2.6%; p < 0.001), fat mass (4.5%; p = 0.002), resting glucose (6.8%; p = 0.017), and HbA1c (3.7%; p = 0.047) decreased, while relative V ˙ O2peak (16%; p < 0.001) increased in the exercise group. Leptin, adiponectin, CTX, osteocalcin or BAP did not change in either group. In conclusion, small dose of aerobic exercise improves key markers of metabolic health in PMW with obesity without negatively affecting markers of bone metabolism.

Promoting healthy populations as a pandemic preparedness strategy: a simulation study from Mexico

Background

The underlying health status of populations was a major determinant of the impact of the COVID-19 pandemic, particularly obesity prevalence. Mexico was one of the most severely affected countries during the COVID-19 pandemic and its obesity prevalence is among the highest in the world. It is unknown by how much the COVID-19 burden could have been reduced if systemic actions had been implemented to reduce excess weight in Mexico before the onset of the pandemic.

Methods

Using a dynamic epidemic model based on nationwide data, we compare actual deaths with those under hypothetical scenarios assuming a lower body mass index in the Mexican population, as observed historically. We also model the number of deaths that would have been averted due to earlier implementation of front-of-pack warning labels or due to increases in taxes on sugar-sweetened beverages and non-essential high-energy foods in Mexico.

Findings

We estimate that 52.5% (95% prediction interval (PI) 43.2, 61.6%) of COVID-19 deaths were attributable to obesity for adults aged 20-64 and 23.8% (95% PI 18.7, 29.1%) for those aged 65 and over. Had the population BMI distribution remained as it was in 2000, 2006, or 2012, COVID-19 deaths would have been reduced by an expected 20.6% (95% PI 16.9, 24.6%), 9.9% (95% PI 7.3, 12.9%), or 6.9% (95% PI 4.5, 9.5%), respectively. If the food-labelling intervention introduced in 2020 had been introduced in 2018, an expected 6.2% (95% PI 5.2, 7.3%) of COVID-19 deaths would have been averted. If taxes on sugar-sweetened beverages and high-energy foods had been doubled, trebled, or quadrupled in 2018, COVID-19 deaths would have been reduced by an expected 4.1% (95% PI 2.5, 5.7%), 7.9% (95% PI 4.9, 11.0%), or 11.6% (95% PI 7.3, 15.8%), respectively.

Interpretation

Public health interventions targeting underlying population health, including non-communicable chronic diseases, is a promising line of action for pandemic preparedness that should be included in all pandemic plans.

Funding

This study received funding from Bloomberg Philanthropies, awarded to Juan A. Rivera from the National Institute of Public Health; Community Jameel, the UK Medical Research Council (MRC), Kenneth C Griffin, and the World Health Organization.

Partial substitutions of animal with plant protein foods in Canadian diets have synergies and trade-offs among nutrition, health and climate outcomes

Dietary guidelines emphasize the consumption of plant protein foods, but the implications of replacing animal with plant sources on a combination of diet sustainability dimensions are unknown. Using a combination of data from a national nutrition survey, greenhouse gas emissions from dataFIELD and relative risks from the Global Burden of Disease Study 2017, we assess the impact of partially substituting red and processed meat or dairy with plant protein foods in Canadian self-selected diets on nutrition, health and climate outcomes. The substitutions induced minor changes to the percentage of the population below requirements for nutrients of concern, but increased calcium inadequacy by up to 14% when dairy was replaced. Replacing red and processed meat or dairy increased life expectancy by up to 8.7 months or 7.6 months, respectively. Diet-related greenhouse gas emissions decreased by up to 25% for red and processed meat and by up to 5% for dairy replacements. Co-benefits of partially substituting red and processed meat with plant protein foods among nutrition, health and climate outcomes are relevant for reshaping consumer food choices in addressing human and planetary health.

Frailty modifies the association of body mass index with mortality among older adults: Kyoto-Kameoka study

BACKGROUND & AIMS

The differences in the association of body mass index (BMI) with mortality between older adults with and without frailty remain unclear. This study investigated this association in community-dwelling older adults with and without frailty.

METHODS

This prospective study included 10,912 adults aged ≥65 years who provided valid responses to a baseline mail survey questionnaire in the Kyoto-Kameoka Study in Japan. The BMI was calculated based on self-reported height and body weight and classified into four categories: <18.5, 18.5-21.4, 21.5-24.9, and ≥25.0 kg/m2. Frailty was evaluated using the validated Kihon Checklist and defined as a score of 7 or higher out of a possible 25 points. Mortality data were collected from 30 July 2011 to 30 November 2016. Hazard ratios (HR) for all-cause mortality were calculated using a multivariable Cox proportional hazards model.

RESULTS

During the 5.3 year median follow-up period (54,084 person-years), 1352 deaths were recorded. After adjusting for confounders, including lifestyle and medical history, compared with participants with a BMI of 21.5-24.9 kg/m2, those in the lower BMI category had a higher mortality HR, while those with a higher BMI displayed an inverse association with mortality (<18.5 kg/m2: HR: 1.85, 95% confidence interval [CI]: 1.58-2.17; 18.5-21.4 kg/m2: HR: 1.38, 95% CI: 1.21-1.58; and ≥25.0 kg/m2: HR: 0.80, 95% CI: 0.67-0.96). In a model stratified by frailty status, the BMI range with the lowest HR for mortality was 23.0-24.0 kg/m2 in non-frail older adults; however, in frail older adults, a higher BMI was inversely associated with mortality.

CONCLUSIONS

The relationship between BMI and mortality varies between individuals with and without frailty, with those experiencing frailty potentially benefiting from a higher BMI compared to those without frailty. This study suggests that frailty should be assessed when considering the optimal BMI for the lowest mortality risk among older adults.

Biomarkers of Metabolic Adaptation to High Dietary Fats in a Mouse Model of Obesity Resistance

Obesity-resistant (non-responder, NR) phenotypes that exhibit reduced susceptibility to developing obesity despite being exposed to high dietary fat are crucial in exploring the metabolic responses that protect against obesity. Although several efforts have been made to study them in mice and humans, the individual protective mechanisms are poorly understood. In this exploratory study, we used a polygenic C57BL/6J mouse model of diet-induced obesity to show that NR mice developed healthier fat/lean body mass ratios (0.43 ± 0.05) versus the obesity-prone (super-responder, SR) phenotypes (0.69 ± 0.07, p < 0.0001) by upregulating gene expression networks that promote the accumulation of type 2a, fast-twitch, oxidative muscle tissues. This was achieved in part by a metabolic adaptation in the form of blood glucose sparing, thus aggravating glucose tolerance. Resistance to obesity in NR mice was associated with 4.9-fold upregulated mitoferrin 1 (Slc25a37), an essential mitochondrial iron importer. SR mice also showed fecal volatile metabolite signatures of enhanced short-chain fatty acid metabolism, including increases in detrimental methyl formate and ethyl propionate, and these effects were reversed in NR mice. Continued research into obesity-resistant phenotypes can offer valuable insights into the underlying mechanisms of obesity and metabolic health, potentially leading to more personalized and effective approaches for managing weight and related health issues.

The Effects of a High-Carbohydrate versus a High-Fat Shake on Biomarkers of Metabolism and Glycemic Control When Used to Interrupt a 38-h Fast: A Randomized Crossover Study

This study aimed to determine the impact of various fast-interrupting shakes on markers of glycemic control including glucose, β-hydroxybutyrate (BHB), insulin, glucagon, GLP-1, and GIP. Twenty-seven sedentary adults (twelve female, fifteen male) with overweight or obesity completed this study. One condition consisted of a 38-h water-only fast, and the other two conditions repeated this, but the fasts were interrupted at 24 h by either a high carbohydrate/low fat (HC/LF) shake or an isovolumetric and isocaloric low carbohydrate/high fat (LC/HF) shake. The water-only fast resulted in 135.3% more BHB compared to the HC/LF condition (p < 0.01) and 69.6% more compared to the LC/HF condition (p < 0.01). The LC/HF condition exhibited a 38.8% higher BHB level than the HC/LF condition (p < 0.01). The area under the curve for glucose was 14.2% higher in the HC/LF condition than in the water condition (p < 0.01) and 6.9% higher compared to the LC/HF condition (p < 0.01), with the LC/HF condition yielding 7.8% more glucose than the water condition (p < 0.01). At the 25-h mark, insulin and glucose-dependent insulinotropic polypeptide (GIP) were significantly elevated in the HC/LF condition compared to the LC/HF condition (p < 0.01 and p = 0.02, respectively) and compared to the water condition (p < 0.01). Furthermore, insulin, GLP-1, and GIP were increased in the LC/HF condition compared to the water condition at 25 h (p < 0.01, p = 0.015, and p < 0.01, respectively). By the 38-h time point, no differences were observed among the conditions for any of the analyzed hormones. While a LC/HF shake does not mimic a fast completely, it does preserve some of the metabolic changes including elevated BHB and glucagon, and decreased glucose and insulin compared to a HC/LF shake, implying a potential for improved metabolic health.

Cost Effectiveness of Calorie Labeling at Large Fast-Food Chains Across the U.S

INTRODUCTION

Calorie labeling of standard menu items has been implemented at large restaurant chains across the U.S. since 2018. The objective of this study was to evaluate the cost effectiveness of calorie labeling at large U.S. fast-food chains.

METHODS

This study evaluated the national implementation of calorie labeling at large fast-food chains from a modified societal perspective and projected its cost effectiveness over a 10-year period (2018-2027) using the Childhood Obesity Intervention Cost-Effectiveness Study microsimulation model. Using evidence from over 67 million fast-food restaurant transactions between 2015 and 2019, the impact of calorie labeling on calorie consumption and obesity incidence was projected. Benefits were estimated across all racial, ethnic, and income groups. Analyses were performed in 2022.

RESULTS

Calorie labeling is estimated to be cost saving; prevent 550,000 cases of obesity in 2027 alone (95% uncertainty interval=518,000; 586,000), including 41,500 (95% uncertainty interval=33,700; 50,800) cases of childhood obesity; and save $22.60 in healthcare costs for every $1 spent by society in implementation costs. Calorie labeling is also projected to prevent cases of obesity across all racial and ethnic groups (range between 126 and 185 cases per 100,000 people) and all income groups (range between 152 and 186 cases per 100,000 people).

CONCLUSIONS

Calorie labeling at large fast-food chains is estimated to be a cost-saving intervention to improve long-term population health. Calorie labeling is a low-cost intervention that is already implemented across the U.S. in large chain restaurants.

Predicting high-risk periods for weight regain following initial weight loss

OBJECTIVE

The aim of this study was to develop a predictive algorithm of "high-risk" periods for weight regain after weight loss.

METHODS

Longitudinal mixed-effects models and random forest regression were used to select predictors and develop an algorithm to predict weight regain on a week-to-week basis, using weekly questionnaire and self-monitoring data (including daily e-scale data) collected over 40 weeks from 46 adults who lost ≥5% of baseline weight during an initial 12-week intervention (Study 1). The algorithm was evaluated in 22 adults who completed the same Study 1 intervention but lost <5% of baseline weight and in 30 adults recruited for a separate 30-week study (Study 2).

RESULTS

The final algorithm retained the frequency of self-monitoring caloric intake and weight plus self-report ratings of hunger and the importance of weight-management goals compared with competing life demands. In the initial training data set, the algorithm predicted weight regain the following week with a sensitivity of 75.6% and a specificity of 45.8%; performance was similar (sensitivity: 81%-82%, specificity: 30%-33%) in testing data sets.

CONCLUSIONS

Weight regain can be predicted on a proximal, week-to-week level. Future work should investigate the clinical utility of adaptive interventions for weight-loss maintenance and develop more sophisticated predictive models of weight regain.

Association between doubly labelled water-calibrated energy intake and objectively measured physical activity with mortality risk in older adults

BACKGROUND

Physical activity or biomarker-calibrated energy intake (EI) alone is associated with mortality in older adults; the interaction relationship between the combined use of both factors and mortality has not been examined. We evaluated the relationship between mortality and calibrated EI and step counts in older adults.

METHODS

This prospective study included 4,159 adults aged ≥65 years who participated in the Kyoto-Kameoka study in Japan and wore a triaxial accelerometer between 1 April and 15 November 2013. The calibrated EI was calculated based on a previously developed equation using EI biomarkers. The step count was obtained from the accelerometer ≥ 4 days. Participants were classified into the following four groups: low EI (LEI)/low step counts (LSC) group (EI: <2,400 kcal/day in men and <1,900 kcal/day in women; steps: <5,000 /day), n = 1,352; high EI (HEI)/LSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: <5,000 /day), n = 1,586; LEI/high step counts (HSC) group (EI: <2,400 kcal/day in men and < 1,900 kcal/day in women; steps: ≥5,000 /day), n = 471; and HEI/HSC group (EI: ≥2,400 kcal/day in men and ≥1,900 kcal/day in women; steps: ≥5,000 /day), n = 750. Mortality-related data were collected until 30 November 2016. We performed a multivariable Cox proportional hazard analysis.

RESULTS

The median follow-up period was 3.38 years (14,046 person-years), and 111 mortalities were recorded. After adjusting for confounders, the HEI/HSC group had the lowest all-cause mortality rate compared to other groups (LEI/LSC: reference; HEI/LSC: hazard ratio [HR]: 0.71, 95% confidence interval [CI]: 0.41-1.23; LEI/HSC: HR: 0.59, 95% CI: 0.29-1.19; and HEI/HSC: HR: 0.10, 95% CI: 0.01-0.76). No significant interaction was observed between the calibrated EI and steps with mortality. The spline model showed that 35-42 kcal/100 steps/day of EI/100 steps was associated with the lowest mortality risk.

CONCLUSIONS

HR mortality risk was lowest at 35-42 kcal/100 steps/day, suggesting that very high (≥56 kcal) or low (<28 kcal) EI/100 steps are not inversely associated with mortality. Adherence to optimal EI and adequate physical activity may provide sufficient energy balance to explain the inverse association with mortality among older Japanese adults.

A multi-scale digital twin for adiposity-driven insulin resistance in humans: diet and drug effects

BACKGROUND

The increased prevalence of insulin resistance is one of the major health risks in society today. Insulin resistance involves both short-term dynamics, such as altered meal responses, and long-term dynamics, such as the development of type 2 diabetes. Insulin resistance also occurs on different physiological levels, ranging from disease phenotypes to organ-organ communication and intracellular signaling. To better understand the progression of insulin resistance, an analysis method is needed that can combine different timescales and physiological levels. One such method is digital twins, consisting of combined mechanistic mathematical models. We have previously developed a model for short-term glucose homeostasis and intracellular insulin signaling, and there exist long-term weight regulation models. Herein, we combine these models into a first interconnected digital twin for the progression of insulin resistance in humans.

METHODS

The model is based on ordinary differential equations representing biochemical and physiological processes, in which unknown parameters were fitted to data using a MATLAB toolbox.

RESULTS

The interconnected twin correctly predicts independent data from a weight increase study, both for weight-changes, fasting plasma insulin and glucose levels, and intracellular insulin signaling. Similarly, the model can predict independent weight-change data in a weight loss study with the weight loss drug topiramate. The model can also predict non-measured variables.

CONCLUSIONS

The model presented herein constitutes the basis for a new digital twin technology, which in the future could be used to aid medical pedagogy and increase motivation and compliance and thus aid in the prevention and treatment of insulin resistance.

Availability of calorie information on online menus from chain restaurants in the USA: current prevalence and legal landscape

OBJECTIVE

Federal law requires calorie information on chain restaurant menus. We sought to assess the prevalence of calorie disclosures on online menus and determine if the menus are controlled by restaurants subject to US labelling requirements.

DESIGN

Cross-sectional.

SETTING

Restaurant websites and mobile apps for restaurant located in New York City, Los Angeles, Chicago, and Houston.

PARTICIPANTS

US chain restaurants (top seventy-five by number of outlets) and third-party platforms (TPP): Grubhub, Uber Eats, DoorDash.

RESULTS

There was at least one calorie disclosure (for at least one food or beverage, in at least one location) on sixty-eight of seventy-two (94 %) menus on restaurant websites or apps, thirty-two of fifty-five (58 %) menus on DoorDash, six of forty-nine (12 %) menus on Grubhub and thirty of fifty-nine (51 %) menus on Uber Eats. There was consistent calorie labelling (all foods and beverages, all locations) on forty-three of seventy-two (60 %) menus on restaurant websites or apps, fifteen of fifty-five (27 %) menus on DoorDash, three of forty-nine (6 %) menus on Grubhub and eleven of fifty-nine (19 %) menus on Uber Eats. Only four restaurant chains consistently labelled calories for all items, in all locations, on all platforms where their menus were found. All three TPP provided restaurants the ability to enter and modify menu items, making the menus subject to US labelling requirements. Only Uber Eats provided guidance to restaurants on entering calorie information.

CONCLUSIONS

As consumers increasingly rely on TPP for restaurant ordering, menus on these platforms should include calories in order to promote transparency and nutrition.

No evidence of compensatory changes in energy balance, despite reductions in body weight and liver fat, during dapagliflozin treatment in type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled, cross-over trial (ENERGIZE)

AIM

This study assessed the impact of dapagliflozin on food intake, eating behaviour, energy expenditure, magnetic resonance imaging (MRI)-determined brain response to food cues and body composition in patients with type 2 diabetes mellitus (T2D).

MATERIALS AND METHODS

Patients were given dapagliflozin 10 mg once daily in a randomized, double-blind, placebo-controlled trial with short-term (1 week) and long-term (12 weeks) cross-over periods. The primary outcome was the difference in test meal food intake between long-term dapagliflozin and placebo treatment. Secondary outcomes included short-term differences in test meal food intake, short- and long-term differences in appetite and eating rate, energy expenditure and functional MRI brain activity in relation to food images. We determined differences in glycated haemoglobin, weight, liver fat (by 1 H magnetic resonance spectroscopy) and subcutaneous/visceral adipose tissue volumes (by MRI).

RESULTS

In total, 52 patients (43% were women) were randomized; with the analysis of 49 patients: median age 58 years, weight 99.1 kg, body mass index 35 kg/m2 , glycated haemoglobin 49 mmol/mol. Dapagliflozin reduced glycated haemoglobin by 9.7 mmol/mol [95% confidence interval (CI) 3.91-16.27, p = .004], and body weight (-2.84 vs. -0.87 kg) versus placebo. There was no short- or long-term difference in test meal food intake between dapagliflozin and placebo [mean difference 5.7 g (95% CI -127.9 to 139.3, p = .933); 15.8 g (95% CI -147.7 to 116.1, p = .813), respectively] nor in the rate of eating, energy expenditure, appetite, or brain responses to food cues. Liver fat (median reduction -4.7 vs. 1.95%), but not subcutaneous/visceral adipose tissue, decreased significantly with 12 weeks of dapagliflozin.

CONCLUSIONS

The reduction in body weight and liver fat with dapagliflozin was not associated with compensatory adaptations in food intake or energy expenditure.

Soda expansion in the tropics: The effect on obesity rates among women without piped water at home

Obesity rates and soda consumption are increasing at a worrisome pace in developing countries. In particular, soda companies seem to be targeting areas with poor access to clean water. This paper exploits a natural experiment in Peru and finds evidence that changes in the price of soda generate important effects in terms of obesity among individuals without piped water at home. These significant effects are driven by a combination of a large effect in the consumption of soda and an effect close to zero in the consumption of potential substitutes high in calories. This paper also provides some evidence that a reduction in price of soda reduces diarrhea prevalence, suggesting that some individuals substitute away contaminated water. This evidence suggests that soda taxes might be particularly beneficial among this population in terms of the prevention of obesity and possibly related diseases such as diabetes and cardiovascular diseases. The potential trade-off between obesity and diarrhea needs to be investigated in greater depth.

Menu Labeling and Calories Purchased in Restaurants in a US National Fast Food Chain

Importance

Menu labeling has been implemented in restaurants in some US jurisdictions as early as 2008, but the extent to which menu labeling is associated with calories purchased is unclear.

Objective

To estimate the association of menu labeling with calories and nutrients purchased and assess geographic variation in results.

Design, Setting, and Participants

A cohort study was conducted with a quasi-experimental design using actual transaction data from Taco Bell restaurants from calendar years 2007 to 2014 US restaurants with menu labeling matched to comparison restaurants using synthetic control methods. Data were analyzed from May to October 2023.

Exposure

Menu labeling policies in 6 US jurisdictions.

Main Outcomes and Measures

The primary outcome was calories per transaction. Secondary outcomes included total and saturated fat, carbohydrates, protein, sugar, fiber, and sodium.

Results

The final sample included 2329 restaurants, with menu labeling in 474 (31 468 restaurant-month observations). Most restaurants (94.3%) were located in California. Difference-in-differences model results indicated that customers purchased 24.7 (95% CI, 23.6-25.7) fewer calories per transaction from restaurants in the menu labeling group in the 3- to 24-month follow-up period vs the comparison group, including 21.9 (95% CI, 20.9-22.9) fewer calories in the 3- to 12-month follow-up period and 25.0 (95% CI, 24.0-26.1) fewer calories in the 13- to 24-month follow-up period. Changes in the nutrient content of transactions were consistent with calorie estimates. Findings in California were similar to overall estimates in magnitude and direction; yet, among restaurants outside of California, no association was observed in the 3- to 24-month period. The outcome of menu labeling also differed by item category and time of day, with a larger decrease in the number of tacos vs other items purchased and a larger decrease in calories purchased during breakfast vs other times of the day in the 3- to 24-month period.

Conclusions and Relevance

In this quasi-experimental cohort study, fewer calories were purchased in restaurants with calorie labels compared with those with no labels, suggesting that consumers are sensitive to calorie information on menu boards, although associations differed by location.

A comparative analysis of the cost-utility of the Philippine tax on sweetened beverages as proposed and as implemented

Background

In response to increasing overweight and obesity, the Philippine government introduced a tax on sweetened beverages (SBs) in 2018. Evidence suggests that the beverage industry influenced the final tax design, making it more favourable for industry than the initially proposed bill. This study aimed to compare the relative health and economic benefits of the proposed SB tax with the implemented SB tax.

Methods

Philippine dietary consumption data were combined with price elasticity data from Mexico and data from Australia adapted to the Philippine context to estimate reductions in SB purchases and changes in body mass index (BMI) following the implementation of the tax. A multi-state, multiple-cohort Markov model was used to estimate the change in health-adjusted life years (HALYs) due to reduction in the epidemiology of obesity-related diseases, healthcare cost savings and government taxation revenue, resulting from both the proposed and implemented tax policies, over the lifetime of the 2018 Philippine population.

Findings

The proposed and implemented taxes were modelled to be dominant (cost-saving and improving health). Intervention costs were modelled to be PHP305.2 million (M) (approximately US$6M). Compared to the proposed tax, the implemented tax was modelled to result in a 43.0% smaller reduction in targeted beverage intake (51.1 ml/person/day vs. 89.7 ml/person/day), a 43.5% smaller reduction in BMI (0.35 kg/m2 vs. 0.62 kg/m2), 39.7% fewer HALYs gained (2,503,118 vs. 4,149,030), 39.9% fewer healthcare cost savings (PHP16.4 billion (B) vs. PHP27.3B), and 27.7% less government taxation revenue (PHP426.3B vs. PHP589.4B).

Interpretation

While the implemented tax in the Philippines will benefit population health, it is likely to yield less benefit than the proposed tax. The influence of the food and beverage industry on policy processes has the potential to lessen the benefits of population NCD prevention policies.

Funding

OH was supported to conduct this research by an Australian Government Research Training Program Stipend Scholarship. The funding body had no role in data collection and analysis, or manuscript preparation.

Impact of the ketogenic diet on body fat, muscle mass, and exercise performance: a review

PURPOSE

The purpose of this review was to investigate the effects of the ketogenic diet (KD), on body fat, muscle mass, and exercise performance. As the KD is a subject of ongoing debate, we also present the existing evidence regarding its potential benefits in the aforementioned areas of body fat, muscle mass, and exercise performance.

METHODS

A literature search was conducted using the keywords "ketogenic diet, low-carbohydrate diet, high-fat diet, body fat, muscle mass, and exercise performance" in PubMed, Web of Science, and Google Scholar.

RESULTS

The KD effectively reduced body fat in the short term and, preserved muscle mass during weight loss, however, its impact on exercise performance remains inconclusive owing to various factors.

CONCLUSION

While controversial, it is undeniable that the KD has the potential to affect body fat, muscle mass, and exercise performance. Consequently, additional research is required to elucidate the underlying mechanisms across various populations, optimize their implementation, and understand their long-term effects.

Distribution of water turnover by sex and age as estimated by prediction equation in Japanese adolescents and adults: the 2016 National Health and Nutrition Survey, Japan

BACKGROUND

Although water is essential to the maintenance of health and life, standard values for human water requirements are yet to be determined. This study aimed to evaluate the distribution of water turnover (WT) according to sex and age, estimated using a prediction equation, in Japanese adolescents and adults.

METHODS

This cross-sectional study used data from the 2016 National Health and Nutrition Survey, Japan. Data were obtained from electronically available aggregated reports in the survey's official website. Participants aged between 15 and 80 years (10,546 men, 12,355 women) were selected using stratified random sampling. WT was calculated considering lifestyle and environmental factors, and using an equation (coefficient of determination = 0.471) previously developed by the international doubly labelled water (DLW) database group. As data on physical activity levels (PAL) were not collected in the survey, we used two evaluation methods: (1) energy intake assessed by dietary records and (2) total energy expenditure measured by the DLW method reported in previous Japanese studies, divided by basal metabolic rate predicted using the equation. We evaluated the relationship between WT and age using a restricted cubic spline model.

RESULTS

The average WT for the 15-19, 20-29, 30-39, 40-49, 50-59, 60-69, and ≥ 70 years was 3291, 3151, 3213, 3243, 3205, 3104, and 2790 ml/day, respectively in men, and 2641, 2594, 2741, 2739, 2753, 2707, and 2482 ml/day, respectively in women. In the spline model, WT showed an inverse association with age in men older than 50 years, whereas women showed a reverse U-shaped relationship between WT and age (p for non-linearity < 0.001), although results differed with body weight adjustment. Similar results were found for both PAL evaluation methods, and the range of WT per body weight was 45-56 ml/day for both sexes.

CONCLUSIONS

We determined the standard values of WT in Japanese population using a prediction equation and national large-scale survey data. These findings may be useful for setting water requirements for dietary guidelines in future.

Semaglutide: a new drug for the treatment of obesity

Semaglutide (▼Ozempic solution for injection, ▼Rybelsus tablets-Novo Nordisk) was initially granted market authorisation for the treatment of type 2 diabetes as an adjunct to diet and exercise. In 2021 and 2022, regulatory agencies in the USA and Europe licensed semaglutide (▼Wegovy solution for injection-Novo Nordisk) for the treatment of individuals who are obese, or overweight and who have at least one weight-related comorbidity. Manufacturer-sponsored randomised controlled trials have shown a loss of almost 12% of body weight over a 68-week period, however, once the medication is stopped people regain most of their pretreatment weight. Gastrointestinal adverse events occur commonly with semaglutide, and pancreatitis, diabetic retinopathy and severe allergic reactions have also been reported. Extensive hype in social and general media has resulted in increased demand for semaglutide leading to supply problems across the various licensed products including those used for treatment of diabetes. In the UK, the National Institute for Health and Care Excellence has recommended semaglutide as an option for weight management for a maximum treatment duration of 2 years. Further studies are underway to assess the effect of semaglutide on longer-term health benefits.

Physiology of the Weight Loss Plateau after Calorie Restriction, GLP-1 Receptor Agonism, and Bariatric Surgery

Objective

To investigate why different weight loss interventions result in varying durations of weight loss prior to approaching plateaus.

Methods

A validated mathematical model of energy balance and body composition dynamics was used to simulate mean weight loss trajectories in response to intensive calorie restriction, semaglutide 2.4 mg, tirzepatide 10 mg, and Roux en-Y gastric bypass (RYGB) surgery interventions. Each intervention was simulated by varying two model parameters affecting energy intake to fit the observed mean weight loss data. One parameter represented the persistent magnitude of the intervention to shift the system from baseline equilibrium and the other parameter represented the strength of the feedback control circuit relating weight loss to increased appetite.

Results

RYGB surgery resulted in a persistent intervention magnitude more than 4-fold greater than calorie restriction and about double that of tirzepatide and semaglutide. All interventions except calorie restriction substantially weakened the appetite feedback control circuit resulting in an extended period of weight loss prior to the plateau.

Conclusions

These preliminary mathematical modeling results suggest that both GLP-1 receptor agonism and RYGB surgery interventions act to weaken the appetite feedback control circuit regulating body weight and induce greater persistent effects to shift the body weight equilibrium as compared to intensive calorie restriction.

Predicting discretionary food consumption using temporal self-regulation theory and food reward sensitivity

Discretionary foods account for over a third of the average adult's total daily energy intake. But its excess consumption is a risk factor for obesity, Type 2 diabetes, and other diet-related diseases. This study aimed to use temporal self-regulation theory (intention, past behaviour, habit, self-regulatory capacity) and food reward sensitivity to identify predictors of discretionary food consumption. Two hundred and seventy-three participants aged between 18 and 80 (M = 42.55, SD = 17.07) comprising of mostly females (79.5%) and those residing in Australia (93.4%), completed a two-part online survey, one week apart. Participants completed measures of intention, past behaviour, habit, self-regulatory capacity, food reward sensitivity and demographic information at time one, and discretionary food consumption at time two. Data was analysed using a hierarchical multiple regression analysis. All variables in combination accounted for a significant 40.3% of the variance in discretionary food consumption (R2 = 0.40, p < .001). However, past behaviour and intention were the only unique significant predictors of discretionary food consumption. No significant moderation effects found. Findings offer insight into the motivators of discretionary food consumption, which can inform the development of effective interventions to reduce discretionary food consumption. Past behaviour should be considered, and intention targeted in interventions to reduce discretionary food consumption.

Projected health and economic impacts of sugar-sweetened beverage taxation in Germany: A cross-validation modelling study

BACKGROUND

Taxes on sugar-sweetened beverages (SSBs) have been implemented globally to reduce the burden of cardiometabolic diseases by disincentivizing consumption through increased prices (e.g., 1 peso/litre tax in Mexico) or incentivizing industry reformulation to reduce SSB sugar content (e.g., tiered structure of the United Kingdom [UK] Soft Drinks Industry Levy [SDIL]). In Germany, where no tax on SSBs is enacted, the health and economic impact of SSB taxation using the experience from internationally implemented tax designs has not been evaluated. The objective of this study was to estimate the health and economic impact of national SSBs taxation scenarios in Germany.

METHODS AND FINDINGS

In this modelling study, we evaluated a 20% ad valorem SSB tax with/without taxation of fruit juice (based on implemented SSB taxes and recommendations) and a tiered tax (based on the UK SDIL) in the German adult population aged 30 to 90 years from 2023 to 2043. We developed a microsimulation model (IMPACTNCD Germany) that captures the demographics, risk factor profile and epidemiology of type 2 diabetes, coronary heart disease (CHD) and stroke in the German population using the best available evidence and national data. For each scenario, we estimated changes in sugar consumption and associated weight change. Resulting cases of cardiometabolic disease prevented/postponed and related quality-adjusted life years (QALYs) and economic impacts from healthcare (medical costs) and societal (medical, patient time, and productivity costs) perspectives were estimated using national cost and health utility data. Additionally, we assessed structural uncertainty regarding direct, body mass index (BMI)-independent cardiometabolic effects of SSBs and cross-validated results with an independently developed cohort model (PRIMEtime). We found that SSB taxation could reduce sugar intake in the German adult population by 1 g/day (95%-uncertainty interval [0.05, 1.65]) for a 20% ad valorem tax on SSBs leading to reduced consumption through increased prices (pass-through of 82%) and 2.34 g/day (95%-UI [2.32, 2.36]) for a tiered tax on SSBs leading to 30% reduction in SSB sugar content via reformulation. Through reductions in obesity, type 2 diabetes, and cardiovascular disease (CVD), 106,000 (95%-UI [57,200, 153,200]) QALYs could be gained with a 20% ad valorem tax and 192,300 (95%-UI [130,100, 254,200]) QALYs with a tiered tax. Respectively, €9.6 billion (95%-UI [4.7, 15.3]) and €16.0 billion (95%-UI [8.1, 25.5]) costs could be saved from a societal perspective over 20 years. Impacts of the 20% ad valorem tax were larger when additionally taxing fruit juice (252,400 QALYs gained, 95%-UI [176,700, 325,800]; €11.8 billion costs saved, 95%-UI [€6.7, €17.9]), but impacts of all scenarios were reduced when excluding direct health effects of SSBs. Cross-validation with PRIMEtime showed similar results. Limitations include remaining uncertainties in the economic and epidemiological evidence and a lack of product-level data.

CONCLUSIONS

In this study, we found that SSB taxation in Germany could help to reduce the national burden of noncommunicable diseases and save a substantial amount of societal costs. A tiered tax designed to incentivize reformulation of SSBs towards less sugar might have a larger population-level health and economic impact than an ad valorem tax that incentivizes consumer behaviour change only through increased prices.

Building upon the sugar beverage tax in Mexico: a modelling study of tax alternatives to increase benefits

INTRODUCTION

In 2014, Mexico implemented a one peso-per-litre tax to sugar-sweetened beverage (SSB). Even though this tax reduced household purchases and predicted population health gains, the magnitude is lower compared with taxes implemented in other settings. In this study, we assessed what would happen if Mexico modified its existing tax to get higher benefits based on currently implemented taxes elsewhere.

METHODS

For each tax scenario, we estimated net benefits as the difference between healthcare savings and lost jobs. We created hypothetical scenarios in which the current tax doubled or would be modified based on existing tax designs around the world including specific taxes (sugar-density or volumetric) and ad-valorem taxes.

RESULTS

We found that the largest benefits would correspond to a tax increase of 7.4 Mexican pesos (0.45 US dollars (USD)) per SSB litre, following the current tax in Bahrain (the highest tax rate option). This tax is predicted to yield net benefits equivalent to USD 24.7 billion after 10 years of the tax redesign. We also found that sugar-density taxes can result in larger net benefits since, in addition to reductions in consumption associated with responses to prices, they induce product reformulation. Middle-income households are the most benefited group because they reported the highest baseline prevalence of obesity and the largest price elasticity.

CONCLUSION

Policymakers should consider pursuing a tax reform adding to the current tax, with significant increases in prices linked to a sugar-density strategy to reach a higher benefit.

Implication of lipid turnover for the control of energy balance

The ongoing obesity epidemic is a consequence of a progressive energy imbalance. The energy-balance model (EBM) posits that obesity results from an excess in food intake and circulating fuels. A reversal in causality has been proposed recently in the form of the carbohydrate-insulin model (CIM), according to which fat storage drives energy imbalance. Under the CIM, dietary carbohydrates shift energy use in favour of storage in adipose tissue. The dynamics of lipid storage and mobilization could, therefore, be sensitive to changes in carbohydrate intake and represent a measurable component of the CIM. To characterize potential changes in lipid dynamics induced by carbohydrates, mathematical models were used. Here, we propose a coherent mathematical implementation of the CIM-energy deposition model (CIM-EDM), which includes lipid turnover dynamics. Using lipid turnover data previously obtained by radiocarbon dating, we build two cohorts of virtual patients and simulate lipid dynamics during ageing and weight loss. We identify clinically testable lipid dynamic parameters that discriminate between the CIM-EDM and an energy in, energy out implementation of the EBM (EBM-IOM). Using a clinically relevant two-month virtual trial, we additionally identify scenarios and propose mechanisms whereby individuals may respond differently to low-carbohydrate diets. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

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)'.

Veganism and body weight: An N of 1 self-experiment

The causal effect that veganism has on body weight has not been scientifically examined. An N of 1 self-experiment was conducted in which blinded body weight and additional behavioural and psychological measures were assessed during two phases of vegan vs. non-vegan lifestyle adherence. In study phase 1, body weight change was -0.8 kg over 1 month of veganism (vs. +0.5 kg non-vegan month). In study phase 2, weight change was -1.2 kg over two veganism months (vs. +1.6 kg non-vegan months). Behavioural and psychological measures were similar during vegan vs. non-vegan periods. Veganism appeared to reduce body weight in this N of 1 self-experiment.

Cost-benefit analysis of alternative tax policies on sugar-sweetened beverages in Mexico

In 2014, Mexico implemented a tax on sugar-sweetened beverages (SSB) equivalent to one Mexican peso (MP) per liter to address the high obesity prevalence. This tax has effectively reduced SSB purchases and yielded healthcare savings; however, it remains unknown whether SSB taxes lead to net benefits at the societal level in Mexico. Moreover, public health experts recommend increasing the tax. The objective of this study is to estimate the net benefits of SSB taxes compared to a scenario of no tax in urban Mexico. Taxes include the one-MP tax and alternative higher taxes (two and three MP per SSB liter). Thus, we conducted a cost-benefit analysis from the perspective of the government, producers, and consumers for a simulated closed cohort of adults in a life-table model. We defined net benefits as the difference between economic benefits (the value of statistical life, healthcare savings, and tax revenue) and costs (consumer surplus and profit losses). We found that, at the societal level, all simulated taxes will eventually generate benefits that surpass costs within ten years. Overall net benefits can reach USD 7.1 billion and 15.3 billion for the one-MP and the three-MP tax, respectively. Hence, these benefits increased at a declining rate compared to taxes. The government and consumers will experience overall positive net benefits among society's members. Policymakers should consider time horizons and tradeoffs between health gains and economic outcomes across different society members.

Criterion validity of wrist accelerometry for assessing energy intake via the intake-balance technique

BACKGROUND

Intake-balance assessments measure energy intake (EI) by summing energy expenditure (EE) with concurrent change in energy storage (ΔES). Prior work has not examined the validity of such calculations when EE is estimated via open-source techniques for research-grade accelerometry devices. The purpose of this study was to test the criterion validity of accelerometry-based intake-balance methods for a wrist-worn ActiGraph device.

METHODS

Healthy adults (n = 24) completed two 14-day measurement periods while wearing an ActiGraph accelerometer on the non-dominant wrist. During each period, criterion values of EI were determined based on ΔES measured by dual X-ray absorptiometry and EE measured by doubly labeled water. A total of 11 prediction methods were tested, 8 derived from the accelerometer and 3 from non-accelerometry methods (e.g., diet recall; included for comparison). Group-level validity was assessed through mean bias, while individual-level validity was assessed through mean absolute error, mean absolute percentage error, and Bland-Altman analysis.

RESULTS

Mean bias for the three best accelerometry-based methods ranged from -167 to 124 kcal/day, versus -104 to 134 kcal/day for the non-accelerometry-based methods. The same three accelerometry-based methods had mean absolute error of 323-362 kcal/day and mean absolute percentage error of 18.1-19.3%, versus 353-464 kcal/day and 19.5-24.4% for the non-accelerometry-based methods. All 11 methods demonstrated systematic bias in the Bland-Altman analysis.

CONCLUSIONS

Accelerometry-based intake-balance methods have promise for advancing EI assessment, but ongoing refinement is necessary. We provide an R package to facilitate implementation and refinement of accelerometry-based methods in future research (see paulhibbing.com/IntakeBalance).

Assessing daily energy intake in adult women: validity of a food-recognition mobile application compared to doubly labelled water

Accurate dietary assessment is crucial for nutrition and health research. Traditional methods, such as food records, food frequency questionnaires, and 24-hour dietary recalls (24HR), have limitations, such as the need for trained interviewers, time-consuming procedures, and inaccuracies in estimations. Novel technologies, such as image-based dietary assessment apps, have been developed to overcome these limitations. SNAQ is a novel image-based food-recognition app which, based on computer vision, assesses food type and volume, and provides nutritional information about dietary intake. This cross-sectional observational study aimed to investigate the validity of SNAQ as a dietary assessment tool for measuring energy and macronutrient intake in adult women with normal body weight (n = 30), compared to doubly labeled water (DLW), a reference method for total daily energy expenditure (TDEE). Energy intake was also estimated using a one-day 24HR for direct comparison. Bland-Altman plots, paired difference tests, and Pearson's correlation coefficient were used to assess agreement and relationships between the methods. SNAQ showed a slightly higher agreement (bias = -329.6 kcal/day) with DLW for total daily energy intake (TDEI) compared to 24HR (bias = -543.0 kcal/day). While both SNAQ and 24HR tended to underestimate TDEI, only 24HR significantly differed from DLW in this regard (p < 0.001). There was no significant relationship between estimated TDEI and TDEE using SNAQ (R2 = 27%, p = 0.50) or 24HR (R2 = 34%, p = 0.20) and there were no significant differences in energy and macronutrient intake estimates between SNAQ and 24HR (Δ = 213.4 kcal/day). In conclusion, these results indicate that SNAQ provides a closer representation of energy intake in adult women with normal body weight than 24HR when compared to DLW, but no relationship was found between the energy estimates of DLW and of the two dietary assessment tools. Further research is needed to determine the clinical relevance and support the implementation of SNAQ in research and clinical settings. Clinical trial registration: This study is registered on ClinicalTrials.gov with the unique identifier NCT04600596 (https://clinicaltrials.gov/ct2/show/NCT04600596).

The health and economic impact and cost effectiveness of interventions for the prevention and control of overweight and obesity in Kenya: a stakeholder engaged modelling study

BACKGROUND

The global increase in mean body mass index has resulted in a substantial increase of non-communicable diseases (NCDs), including in many low- and middle-income countries such as Kenya. This paper assesses four interventions for the prevention and control of overweight and obesity in Kenya to determine their potential health and economic impact and cost effectiveness.

METHODS

We reviewed the literature to identify evidence of effect, determine the intervention costs, disease costs and total healthcare costs. We used a proportional multistate life table model to quantify the potential impacts on health conditions and healthcare costs, modelling the 2019 Kenya population over their remaining lifetime. Considering a health system perspective, two interventions were assessed for cost-effectiveness. In addition, we used the Human Capital Approach to estimate productivity gains.

RESULTS

Over the lifetime of the 2019 population, impacts were estimated at 203,266 health-adjusted life years (HALYs) (95% uncertainty interval [UI] 163,752 - 249,621) for a 20% tax on sugar-sweetened beverages, 151,718 HALYs (95% UI 55,257 - 250,412) for mandatory kilojoule menu labelling, 3.7 million HALYs (95% UI 2,661,365-4,789,915) for a change in consumption levels related to supermarket food purchase patterns and 13.1 million HALYs (95% UI 11,404,317 - 15,152,341) for a change in national consumption back to the 1975 average levels of energy intake. This translates to 4, 3, 73 and 261 HALYs per 1,000 persons. Lifetime healthcare cost savings were approximately United States Dollar (USD) 0.14 billion (USD 3 per capita), USD 0.08 billion (USD 2 per capita), USD 1.9 billion (USD 38 per capita) and USD 6.2 billion (USD 124 per capita), respectively. Lifetime productivity gains were approximately USD 1.8 billion, USD 1.2 billion, USD 28 billion and USD 92 billion. Both the 20% tax on sugar sweetened beverages and the mandatory kilojoule menu labelling were assessed for cost effectiveness and found dominant (health promoting and cost-saving).

CONCLUSION

All interventions evaluated yielded substantive health gains and economic benefits and should be considered for implementation in Kenya.

Progression to Obesity: Variations in Patterns of Metabolic Fluxes, Fat Accumulation, and Gastrointestinal Responses

Obesity is a multifactorial disorder that is remarkably heterogeneous. It presents itself in a variety of phenotypes that can be metabolically unhealthy or healthy, associate with no or multiple metabolic risk factors, gain extreme body weight (super-responders), as well as resist obesity despite the obesogenic environment (non-responders). Progression to obesity is ultimately linked to the overall net energy balance and activity of different metabolic fluxes. This is particularly evident from variations in fatty acids oxidation, metabolic fluxes through the pyruvate-phosphoenolpyruvate-oxaloacetate node, and extracellular accumulation of Krebs cycle metabolites, such as citrate. Patterns of fat accumulation with a focus on visceral and ectopic adipose tissue, microbiome composition, and the immune status of the gastrointestinal tract have emerged as the most promising targets that allow personalization of obesity and warrant further investigations into the critical issue of a wider and long-term weight control. Advances in understanding the biochemistry mechanisms underlying the heterogenous obesity phenotypes are critical to the development of targeted strategies to maintain healthy weight.