Physical activity does not influence obesity risk: time to clarify the public health message

The neurobiology of overeating

Food intake serves to maintain energy homeostasis; however, overeating can result in obesity, which is associated with serious health complications. In this review, we explore the intricate relationship between overeating, obesity, and the underlying neurobiological mechanisms. We review the homeostatic and hedonic feeding systems, highlighting the role of the hypothalamus and reward systems in controlling food intake and energy balance. Dysregulation in both these systems leads to overeating, as seen in genetic syndromes and environmental models affecting appetite regulation when consuming highly palatable food. The concept of "food addiction" is examined, drawing parallels to drug addiction. We discuss the cellular substrate for addiction-related behavior and current pharmacological obesity treatments-in particular, GLP-1 receptor agonists-showcasing synaptic plasticity in the context of overeating and palatable food exposure. A comprehensive model integrating insights from addiction research is proposed to guide effective interventions for maladaptive feeding behaviors. Ultimately, unraveling the neurobiological basis of overeating holds promise for addressing the pressing public health issue of obesity.

Objectively measured moderate-to-vigorous physical activity does not attenuate prospective weight gain among african-origin adults spanning the epidemiological transition

Traditional obesity-related public health messaging often includes physical activity (PA) recommendations. However, at the population level, the data are conflicting, especially when comparing different self-reported vs. measured techniques across different settings and populations. We measured the association between moderate-to-vigorous intensity PA (MVPA) and prospective weight change across five African-origin populations and the extent to which MVPA attenuated weight change over time. At baseline, 2,500 adults (median age: 37y) were recruited into the Modelling the Epidemiologic Transition Study (METS), from Ghana, South Africa, Jamaica, Seychelles, and US. 2000 participants were followed up 8 years later, with 851 participants having complete 7-day accelerometry to measure MVPA at both time points. Generalised estimating equations were used to explore the longitudinal association between weight and MVPA adjusted for several confounders. The obesity prevalence at baseline was 27.5% which increased to 38.0% at follow-up. Baseline MVPA varied from 7 (IQR: 4, 16) min/day in US women to 52 (IQR: 36, 78) min/day in South African men, and similarly at follow-up ranged from 8 min/day to 41 min/day among the same participant groups. While overall, engaging in higher MVPA levels was associated with a lower body weight, such that every additional 30 min of MVPA equalled a 600 g lower body weight (p = 0.04), the interaction between time and MVPA was not statistically significant (p = 0.18). Therefore, regardless of the amount of MVPA at any time point, body weight increased over time. Despite the association between MVPA and weight, our results suggest that objectively measured longitudinal MVPA was not associated with the change in 8-year weight in African-origin adults. Our research confirms that while PA is a critical determinant of cardiovascular health, it alone may not be enough to stem the rising obesity burden.

Objectively measured moderate-to-vigorous physical activity does not attenuate prospective weight gain among African-origin adults spanning the epidemiological transition

Traditional obesity-related public health messaging often includes physical activity (PA) recommendations. However, at the population level, the data are conflicting, especially when comparing different self-reported vs measured techniques across different settings and populations. We measured the association between moderate-to-vigorous intensity PA (MVPA) and prospective weight change across five African-origin populations and the extent to which MVPA attenuated weight change over time. At baseline, 2,500 adults (median age: 37y) were recruited into the Modelling the Epidemiologic Transition Study (METS), from Ghana, South Africa, Jamaica, Seychelles, and US. 2000 participants were followed up 8 years later, with 851 participants having complete 7-day accelerometry to measure MVPA at both time points. Generalised estimating equations were used to explore the longitudinal association between weight and MVPA adjusted for several confounders. The obesity prevalence at baseline was 27.5% which increased to 38.0% at follow-up. Baseline MVPA varied from 7 (IQR: 4, 16) min/day in US women to 52 (IQR: 36, 78) min/day in South African men, and similarly at follow-up ranged from 8 min/day to 41 min/day among the same participant groups. While overall, engaging in higher MVPA levels was associated with a lower body weight, such that every additional 30 min of MVPA equalled a 600g lower body weight (p = 0.04), the interaction between time and MVPA was not statistically significant (p = 0.18). Therefore, regardless of the amount of MVPA at any time point, body weight increased over time. Despite the association between MVPA and weight, our results suggest that objectively measured longitudinal MVPA was not associated with the change in 8-year weight in African-origin adults. Our research confirms that while PA is a critical determinant of cardiovascular health, it alone may not be enough to stem the rising obesity burden.

The impact of early sports participation on body fatness in adulthood is not mediated by current physical activity

OBJECTIVE

The aim was to analyze the relationship between early sports participation (ESP) and body fatness (BF) in adults, as well as to identify whether this possible relationship is directly influenced by the current physical activity (PA) level.

METHODS

This cross-sectional study combined baseline data of two cohort. The BF estimated by DXA. The ESP, the subjects reported the engagement in sports during childhood (7-10 years) and adolescence (11-17 years) through two yes/no questions and current PA (described as steps) was device-measured using pedometers. Were identified as potential covariates and therefore adjusted the multivariate models: age, ethnicity, alcohol consumption, smoking, and sleep quality. Statistical analysis consisted of the chi-square test, analysis of variance/covariance, and structural equation modeling (software BioEstat version 5.0; p-value < .05).

RESULTS

Adults engaged in ESP had lower BF; among women, the variance in BF explained by ESP was 25.5%; among men, it was 9.2%. Sports participation in early life (r = -.436 [95% CI: -0.527 to -0.346]) and current PA (r = -.431 [95% CI: -0.522 to -0.340]) were inversely related to BF, as well as positively related to each other (r = .328 [95% CI: 0.226 to 0.430]). In the mediation model, current PA partially mediated (18.5%) the impact of ESP on BF, while current PA and ESP remained relevant determinants of BF.

CONCLUSION

Early sports participation and current PA have a significant impact on BF in adulthood, which is of similar magnitude and independent of each other.

Update on the Obesity Epidemic: After the Sudden Rise, Is the Upward Trajectory Beginning to Flatten?

PURPOSE OF REVIEW

To provide an update on current obesity prevalence trends and summarize the available evidence suggesting a possible plateau or stabilization in obesity rates after the previous sudden global rise.

RECENT FINDINGS

The escalating global obesity epidemic represents one of the most serious public health challenges. There have been some indications that in high-income populations, the rate of obesity increase in adults has been stabilized after the decade 2000-2010, suggesting a possible plateau. Current evidence also suggests that obesity rates have been stabilized in children and adolescents of most economically advanced countries since 2000, which is possibly related to healthier dietary habits and increased levels of physical activity. On the other hand, there is a steady uninterrupted rise in low-income nations, and the universal trend is obesity escalation rather than slowdown, mainly driven by sharp increases in the obesity prevalence of low-income populations. Furthermore, an increasing number of high- and middle-income countries are currently experiencing an epidemic of severe obesity. In high-income populations, severe obesity is expected to double its prevalence from 10 to 20% between 2020 and 2035, posing an enormous threat for healthcare systems. Even if transiently stabilized, the obesity prevalence remains globally at unacceptably high levels, and there is no guarantee that the current stability (if any) will be maintained for long. In this review, we explore the underlying drivers of the global obesity epidemic; we provide possible explanations for the reported slowdown of the obesity rates in some countries; and we overall take a critical perspective on the obesity plateau hypothesis, emphasizing the urgent need for immediate effective actions at population and regional level in order to halt the alarming obesity escalation and its serious health risks.

The Effectiveness of Nutritional Strategies in the Treatment and Management of Obesity: A Systematic Review

Obesity, a condition primarily resulting from positive energy balance, has become a significant global health concern. Numerous studies have demonstrated that obesity is a major risk factor for various illnesses, including different types of cancer, coronary heart disease, sleep apnea, CV stroke, type II diabetes mellitus, etc. To effectively address this issue, prevention and treatment approaches to manage body weight are crucial. There are several evidence-based approaches available for the treatment and management of obesity, taking into account factors such as body mass index classification, individual weight history, and existing comorbidities. To facilitate successful obesity treatment and management, there are pragmatic approaches and tools available, including the reduction of energy density, portion control, and diet quality enhancement. These approaches encompass the use of medications, lifestyle interventions, bariatric surgery, and formula diets. Regardless of the specific method employed, behavior change, reduction of energy intake, and increased energy expenditure are integral components for successful treatment and management of obesity. These measures allow patients to personalize and customize their dietary patterns, leading to effective and sustainable weight reduction. Incorporating physical activities and self-monitoring of individual diets are effective techniques for promoting behavior change in obesity and weight management. The main objective of this systematic review is to evaluate the effectiveness of dietary/nutritional interventions in the treatment and management of obesity through provision of valuable insights into the effectiveness of such nutritional strategies. To attain this, a comprehensive analysis of various dietary approaches and their impacts on weight will be conducted.

How can physical activity facilitate a sustainable future? Reducing obesity and chronic disease

This review examines the ways in which physical activity can contribute to a sustainable future by addressing significant public health issues. The review begins by identifying obesity and ageing as two major challenges facing societies around the world due to the association of both with the risk of chronic disease. Recent developments in the understanding and treatment of obesity are examined followed by an appraisal of the role of exercise alone and in combination with other therapies in preventing and managing obesity. The review then addresses the interaction between exercise and appetite due to the central role appetite plays in the development of overweight and obesity. The final section of the review examines the potential of physical activity to combat age-related chronic disease risk including CVD, cancer and dementia. It is concluded that while bariatric surgery and pharmacotherapy are the most effective treatments for severe obesity, physical activity has a role to play facilitating and enhancing weight loss in combination with other methods. Where weight/fat reduction via exercise is less than expected this is likely due to metabolic adaptation induced by physiological changes facilitating increased energy intake and decreased energy expenditure. Physical activity has many health benefits independent of weight control including reducing the risk of developing CVD, cancer and dementia and enhancing cognitive function in older adults. Physical activity may also provide resilience for future generations by protecting against the more severe effects of global pandemics and reducing greenhouse gas emissions via active commuting.

Physical Activity and Its Association With Body Mass Index: A Cross-Sectional Analysis in Middle-Aged Adults From 4 Sub-Saharan African Countries

BACKGROUND

This study aimed to explore association of self-reported physical activity domains of work, leisure, and transport-related physical activity and body mass index (BMI) in 9388 adult men and women from the Africa-Wits-INDEPTH partnership for Genomic (AWI-Gen) study in Africa. Africa-Wits-INDEPTH partnership for Genomic is a large, population-based cross-sectional cohort with participants from 6 sites from rural and urban areas in 4 sub-Saharan African countries.

METHODS

A sex-stratified meta-analysis of cross-sectional data from men and women aged 29-82 years was used to assess the association of physical activity with BMI.

RESULTS

Overall, meeting physical activity guidelines of at least 150 minutes per week was associated with 0.82 kg/m2 lower BMI in men (β = -0.80 kg/m2; 95% confidence interval [CI], -1.14 to -0.47) and 0.68 kg/m2 lower BMI in women (β = -0.68 kg/m2; 95% CI, -1.03 to -0.33). Sex and site-specific differences were observed in the associations between physical activity domains and BMI. Among those who met physical activity guidelines, there was an inverse association between transport-related physical activity and BMI in men from Nanoro (Burkina Faso) (β = -0.79 kg/m2; 95% CI, -1.25 to -0.33) as well as work-related physical activity and BMI in Navrongo men (Ghana) (β = -0.76 kg/m2; 95% CI, -1.25 to -0.27) and Nanoro women (β = -0.90 kg/m2; 95% CI, -1.44 to -0.36).

CONCLUSIONS

Physical activity may be an effective strategy to curb rising obesity in Africa. More studies are needed to assess the impact of sex and geographic location-specific physical activity interventions on obesity.

Associations of changes in physical activity and diet with incident obesity and changes in adiposity: Longitudinal findings from the UK Biobank

We examined the association of changes in physical activity and diet with obesity development and changes in body fat percentage, body mass index, and waist circumference. 31,344 adults without obesity at baseline (age = 56.0 ± 7.5 years; female = 49.1%) from the UK Biobank were included. Physical activity was categorised based on public health guidelines as: inactive; insufficient; and sufficient. Diet category was assigned based on an established composited score that included consumption of fruits, vegetables, fish, red meat (unprocessed), and processed meat. Diet was categorised as: poor; reasonable; and good. Physical activity and diet changes were categorised based on changes in category: worsened; stable; increased (physical activity)/improved (diet). During a mean follow up of 6.8 (SD = ±2.3) years, 1354 (4.3%) participants developed obesity. Compared to stable physical activity-diet, increasing physical activity was associated with the lowest obesity odds, across diet changes (e.g., OR [95%CI]: diet worsened (0.89 [0.69, 1.15]); diet improved (0.65 [0.48, 0.89])). Increasing physical activity with improved diet was associated with the largest difference in body fat percentage (β:-0.62 [-0.82, -0.41]), body mass index (-0.37 [-0.47, -0.28]), and waist circumference (-1.21 [-1.63, -0.79]). Excluding adults with a history of smoking, or major illness, lowered obesity odds among participants with increased physical activity by an additional 11%-21%. In those who decreased physical activity obesity was attenuated when combined with diet improvement. Improvements in physical activity or diet mutually attenuated the deleterious associations of the other behaviour's deterioration. In most analyses, increases in physical activity conferred consistent positive associations against the development of obesity, across dietary change groups.

The role of physical activity in the regulation of body weight: The overlooked contribution of light physical activity and sedentary behaviors

The role of physical activity (PA) in the regulation of body weight is still a major topic of debate. This may be because studies have essentially focused on the effects of moderate/vigorous PA (MVPA) on body weight while overlooking the other components of PA, namely, light-intensity PA (LPA, daily life activities) and sedentary behaviors (SB, too much sitting). In this review, we will (i) describe the history of changes in PA behaviors that occurred with modernization; (ii) review data from cross-sectional and longitudinal studies that examined the associations between PA, SB, and measures of obesity; (iii) review interventional studies that investigated the effects of changes in PA and SB on body weight and adiposity; and (iv) discuss experimental studies that addressed potential biological mechanisms underlying the effects of PA and SB on weight regulation. Overall recent findings support the importance of considering all components of PA to better understand the regulation of energy balance and suggest an important role for LPA and SB in addition to MVPA on body weight regulation. Longitudinal large-scale rigorous studies are needed to advance our knowledge of the role of PA/SB in combating the obesity epidemic.

Commentary-fat but fit…and cold? Potential evolutionary and environmental drivers of metabolically healthy obesity

As global obesity rates continue to rise, it is important to understand the origin, role and range of human variation of body mass index (BMI) in assessing health and healthcare. A growing body of evidence suggests that BMI is a poor indicator of health across populations, and that there may be a metabolically healthy obese phenotype. Here, we review the reasons why BMI is an inadequate tool for assessing cardiometabolic health. We then suggest that cold climate adaptations may also render BMI an uninformative metric. Underlying evolutionary and environmental drivers may allow for heat conserving larger body sizes without necessarily increasing metabolic health risks. However, there may also be a potential mismatch between modern obesogenic environments and adaptations to cold climates, highlighting the need to further investigate the potential for metabolically healthy obese phenotypes among circumpolar and other populations as well as the broader meaning for metabolic health.

Sociodemographic, lifestyle, behavioral, and parental factors associated with sugar-sweetened beverage consumption in children in China

Objective

Evidence shows sugar-sweetened beverage (SSB) consumption is a risk factor for obesity and non-communicable diseases (NCDs) in children. Investigating the influential profiles, which have been examined insufficiently, will help to inform the reduction of SSB consumption. The present research examines the current trend in SSB consumption and associated factors among children in China, in order to inform policy development.

Methods

Secondary data was extracted from China’s Health and Nutrition Survey (CHNS; 2004, 2006, 2009, and 2011), a repeated cross-sectional research, and a Chi-squared test was applied to compare SSB consumption in the last year, queried by social demographical, `environmental, behavioral, and parental factors. Multilevel mixed-effects logistic regression was employed to examine the trend and effects of the multiple factors.

Results

A total of 6015 Chinese children aged 6–17 years were investigated. From 2004 to 2011, the percentage of SSB consumption in children increased from 72.6% to 90.3%. The prevalence in urban areas was higher than the prevalence in rural areas, higher in high schools than primary and middle schools, higher in east coast affluent provinces than other provinces, and higher in high-income households than low-income households. Other associated factors include children’s fast food and salty snacks preference, level of physical activity, sedentariness, and parental education. The strongest association with SSB consumption in children was the mother’s SSB consumption (adjusted odds ratio: 5.54, 95% CI: 3.17–9.67).

Conclusion

Children’s SSB consumption has increased significantly in China, and is associated with socio-economic, demographic, level of physical activity, food preference, and parental factors. Future strategies aimed at reducing SSB consumption among children need to consider these factors.

Effect of very large body mass loss on energetics, mechanics and efficiency of walking in adults with obesity: mass-driven versus behavioural adaptations

Abstract

Understanding the mechanisms involved in the higher energy cost of walking (NC_w: the energy expenditure above resting per unit distance) in adults with obesity is pivotal to optimizing the use of walking in weight management programmes. Therefore, this study aimed to investigate the mechanics, energetics and mechanical efficiency of walking after a large body mass loss induced by bariatric surgery in individuals with obesity. Nine adults (39.5 ± 8.6 year; BMI: 42.7 ± 4.6 kg m^–2) walked at five fixed speeds before (baseline) and after the bariatric surgery (post 1 and post 2). Gas exchanges were measured to obtain NC_w. A motion analysis system and instrumented treadmill were combined to assess total mechanical work (W_tot). Mechanical efficiency (W_tot NC_w^–1) was also calculated. Participants lost 25.7 ± 3.4% of their body mass at post 1 (6.6 months; P < 0.001) and 6.1 ± 4.9% more at post 2 (12 months; P = 0.014). Mass‐normalized NC_w was similar between baseline and post 1 and decreased at post 2 compared to that at baseline (−6.2 ± 2.7%) and post 1 (−8.1 ± 1.9%; P ≤ 0.007). No difference was found in mass‐normalized W_tot during follow‐up (P = 0.36). Mechanical efficiency was similar at post 1 and post 2 when compared to that at baseline (P ≥ 0.19), but it was higher (+14.1 ± 4.6%) at post 2 than at post 1 (P = 0.013). These findings showed that after a very large body mass loss, individuals with obesity may reorganize their walking pattern into a gait more similar to that of lean adults, thus decreasing their NC_w by making their muscles work more efficiently.

Key points

A higher net (above resting) energy cost of walking (lower gait economy) is observed in adults with obesity compared to lean individuals.

Understanding the mechanisms (i.e. mass driven, gait pattern and behavioural changes) involved in this extra cost of walking in adults with obesity is pivotal to optimizing the use of walking to promote daily physical activity and improve health in these individuals.

We found that very large weight loss induced by bariatric surgery significantly decreased the energy cost of walking per kg of body mass after 1 year with similar total mechanical work per kg of body mass, resulting in an increased mechanical efficiency of walking.

Individuals with obesity may reorganize their walking pattern into a gait more similar to that of adults of normal body mass, thus decreasing their energy cost of walking by making their muscles work more efficiently.

Obesity prevalence in large US cities: association with socioeconomic indicators, race/ethnicity and physical activity

BACKGROUND

Obesity has a complex association with socioeconomic factors. Further clarification of this association could guide population interventions.

METHODS

To determine the relationship between obesity prevalence, socioeconomic indicators, race/ethnicity, and physical activity, we performed a cross-sectional, multivariable linear regression, with data from large US cities participating in the Big Cities Health Inventory.

RESULTS

Increased household income was significantly associated with decreased obesity prevalence, for White (-1.97% per 10 000USD), and Black (-3.02% per 10 000USD) populations, but not Hispanic. These associations remained significant when controlling for the proportion of the population meeting physical activity guidelines. Educational attainment had a co-linear relationship with income, and only a bachelor's degree or higher was associated with a lower prevalence of obesity in White (-0.30% per percentage) and Black (-0.69% per percentage) populations. No association was found between obesity prevalence and the proportion of the population meeting physical activity guidelines for any race/ethnicity grouping.

CONCLUSION

At the population level of large US cities, obesity prevalence is inversely associated with median household income in White and Black populations. Strategies to increase socioeconomic status may also decrease obesity. Targeting attainment of physical activity guidelines as an obesity intervention needs further appraisal.

Childhood Daily Energy Expenditure Does Not Decrease with Market Integration and Is Not Related to Adiposity in Amazonia

BACKGROUND

Childhood overweight and obesity (OW/OB) is increasingly centered in low- and middle-income countries (LMICs) as rural populations experience market integration and lifeway change. Most explanatory studies have relied on imprecise estimates of children's energy expenditure, restricting understanding of the relative effects of changes in diet and energy expenditure on the development of OW/OB in transitioning contexts.

OBJECTIVES

This study used gold-standard measurements of children's energy expenditure to investigate the changes that underlie OW/OB and the nutrition/epidemiologic transition.

METHODS

Cross-sectional data were collected from "rural" (n = 43) Shuar forager-horticulturalist children and their "peri-urban" (n = 34) Shuar counterparts (age 4-12 y) in Amazonian Ecuador. Doubly labeled water measurements of total energy expenditure (TEE; kcal/d), respirometry measurements of resting energy expenditure (REE; kcal/d), and measures of diet, physical activity, immune activity, and market integration were analyzed primarily using regression models.

RESULTS

Peri-urban children had higher body fat percentage (+8.1%, P < 0.001), greater consumption of market-acquired foods (multiple P < 0.001), lower concentrations of immune activity biomarkers (multiple P < 0.05), and lower REE (-108 kcal/d, P = 0.002) than rural children. Despite these differences, peri-urban children's TEE was indistinguishable from that of rural children (P = 0.499). Moreover, although sample-wide IgG concentrations and household incomes predicted REE (both P < 0.05), no examined household, immune activity, or physical activity measures were related to children's overall TEE (all P > 0.09). Diet and energy expenditure associations with adiposity demonstrate that only reported consumption of market-acquired "protein" and "carbohydrate" foods predicted children's body fat levels (multiple P < 0.05).

CONCLUSIONS

Despite underlying patterns in REE, Shuar children's TEE is not reliably related to market integration and-unlike dietary measures-does not predict adiposity. These findings suggest a leading role of changing dietary intake in transitions to OW/OB in LMICs.

Trends of low physical activity among Iranian adolescents across urban and rural areas during 2006-2011

It is well documented that physical inactivity is related to weight gain and a whole host of chronic diseases. This study investigated trends of low physical activity among Iranian adolescents in urban and rural areas between 2006-2011. A total of 12,178 adolescents, aged between 15 and 19 years, participated in National Surveys of Risk Factors for Non-Communicable Diseases. Data on physical activity was obtained using the global physical activity questionnaire. A complex sample survey and multinomial logistic regression were used to model physical activity levels. The percentage of adolescents who had low levels of physical activity increased from 2006 to 2011 in both urban and rural areas. Low and moderate levels of physical activity were lower in rural girls as compared with urban girls, with a prevalence ratio of 0.59 (95% CI 0.47-0.74) and 0.59 (95% CI 0.47-0.74), respectively. The corresponding values for boys residing in rural areas compared with boys in urban areas were 0.56 (95% CI 0.43-0.75) and 0.60 (95% CI 0.48-0.74), respectively. The adolescents' lifestyles showed an increasing trend for physical inactivity in both genders; however, in rural areas, only girls had a rising affinity for a sedentary lifestyle throughout the 2006-2011 years.

Descriptive epidemiology of energy expenditure in the UK: findings from the National Diet and Nutrition Survey 2008-15

Background

Little is known about population levels of energy expenditure, as national surveillance systems typically employ only crude measures. The National Diet and Nutrition Survey (NDNS) in the UK measured energy expenditure in a 10% subsample by gold-standard doubly labelled water (DLW).

Methods

DLW-subsample participants from the NDNS (383 males, 387 females) aged 4–91 years were recruited between 2008 and 2015 (rolling programme). Height and weight were measured and body-fat percentage estimated by deuterium dilution.

Results

Absolute total energy expenditure (TEE) increased steadily throughout childhood, ranging from 6.2 and 7.2 MJ/day in 4- to 7-year-olds to 9.7 and 11.7 MJ/day for 14- to 16-year-old girls and boys, respectively. TEE peaked in 17- to 27-year-old women (10.7 MJ/day) and 28- to 43-year-old men (14.4 MJ/day), before decreasing gradually in old age. Physical-activity energy expenditure (PAEE) declined steadily with age from childhood (87 kJ/day/kg in 4- to 7-year-olds) through to old age (38 kJ/day/kg in 71- to 91-year-olds). No differences were observed by time, region and macronutrient composition. Body-fat percentage was strongly inversely associated with PAEE throughout life, irrespective of expressing PAEE relative to body mass or fat-free mass. Compared with females with <30% body fat, females with >40% recorded 29 kJ/day/kg body mass and 18 kJ/day/kg fat-free mass less PAEE in analyses adjusted for age, geographical region and time of assessment. Similarly, compared with males with <25% body fat, males with >35% recorded 26 kJ/day/kg body mass and 10 kJ/day/kg fat-free mass less PAEE.

Conclusions

This first nationally representative study reports levels of human-energy expenditure as measured by gold-standard methodology; values may serve as a reference for other population studies. Age, sex and body composition are the main determinants of energy expenditure.

Key Messages

This is the first nationally representative study of human energy expenditure, covering the UK in the period 2008-2015.

Total energy expenditure (MJ/day) increases steadily with age throughout childhood and adolescence, peaks in the 3^rd decade of life in women and 4^th decade of life in men, before decreasing gradually in old age.

Physical activity energy expenditure (kJ/day/kg or kJ/day/kg fat-free mass) declines steadily with age from childhood to old age, more steeply so in males.

Body-fat percentage is strongly inversely associated with physical activity energy expenditure.

We found little evidence that energy expenditure varied by geographical region, over time, or by dietary macronutrient composition.

Effects of the Mat Pilates Method on Body Composition: Systematic Review With Meta-Analysis

BACKGROUND

The objective of this systematic review was to determine the efficacy of the mat Pilates method on body composition in healthy adult subjects compared with traditional exercise or control condition models.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, SPORTDiscus, PEDro, SciELO, CINAHAL, and the Cochrane Library.

RESULTS

A total of 10 eligible studies were selected for revision. The findings of this review demonstrated that the mat Pilates method was not more effective than the traditional exercise or control condition models for the analyzed variables (body mass index, lean mass, body fat percentage, and abdominal circumference). Moreover, in the exploratory analysis with older people, adults, and overweight/obese individuals, the mat Pilates method was also not superior for the analyzed outcomes.

CONCLUSION

The findings of this study suggest that the mat Pilates method is no better than the control condition or other types of training to reduce body composition.

Striatal Dopamine D2 Receptors Regulate Cost Sensitivity and Behavioral Thrift

The role of the dopamine D2 receptor (D2R) in regulating appetitive behavior continues to be controversial. Earlier literature suggests that reduced D2R signaling diminishes motivated behavior while more recent theories suggest that reduced D2R, as has been putatively observed in obesity, facilitates compulsive appetitive behavior and promotes overeating. Using a homecage foraging paradigm with mice, we revisit classic neuroleptic pharmacological studies from the 1970s that led to the 'extinction mimicry' hypothesis: that dopamine blockade reduces reinforcement leading to an extinction-like reduction in a learned, motivated behavior. We complement this with a selective genetic deletion of D2R in indirect pathway medium spiny neurons (iMSNs). Administration of haloperidol shifts foraging strategy toward less effortful, more thrifty pursuit of food without altering consumption or bodyweight. D2R deletion in iMSNs also reduces effort and energy expended toward food pursuit, but without a compensatory shift in foraging strategy, resulting in loss of body weight, an effect more pronounced under conditions of escalating costs as the knockouts fail to adequately increase effort. The selective knockouts exhibit no change in sucrose preference or sucrose reinforcement. These data suggest that striatal D2R regulates effort in response to costs, mediating cost sensitivity and behavioral thrift. In the context of obesity, these data suggest that reduced D2R is more likely to diminish effort and behavioral energy expenditure rather than increase appetitive motivation and consumption, possibly contributing to reduced physical activity commonly observed in obesity.

Constraint and trade-offs regulate energy expenditure during childhood

Children's metabolic energy expenditure is central to evolutionary and epidemiological frameworks for understanding variation in human phenotype and health. Nonetheless, the impact of a physically active lifestyle and heavy burden of infectious disease on child metabolism remains unclear. Using energetic, activity, and biomarker measures, we show that Shuar forager-horticulturalist children of Amazonian Ecuador are ~25% more physically active and, in association with immune activity, have ~20% greater resting energy expenditure than children from industrial populations. Despite these differences, Shuar children's total daily energy expenditure, measured using doubly labeled water, is indistinguishable from industrialized counterparts. Trade-offs in energy allocation between competing physiological tasks, within a constrained energy budget, appear to shape childhood phenotypic variation (e.g., patterns of growth). These trade-offs may contribute to the lifetime obesity and metabolic health disparities that emerge during rapid economic development.

Corporate sponsorship of physical activity promotion programmes: part of the solution or part of the problem?

Background

Parklives is a programme intended to raise levels of physical activity across the UK, funded by Coca-Cola GB and delivered in association with Local Authorities and other organizations. Such public-private partnerships have been advocated by many however critics suggest that the conflict between stakeholder motives is too great.

Methods

This study conducted a content analysis of twitter content related to the ParkLives physical activity programme. Images and text were analysed from two separate weeks, one from the school vacation period and one during school term time.

Results

Three hundred and eighteen tweets were analysed. Content analysis revealed 79% of images contained children and 45% of these images contained prominent Coca-Cola branding, a level of exposure that suggests ParkLives simultaneously provides opportunities for children's physical activity and for targeted marketing. Content analysis also demonstrated that the programme allowed increased access to policy-makers.

Conclusions

The sponsorship of a physical activity promotion campaign can allow a corporation to target its marketing at children and gain access to health-related policy development networks. This study reinforces the need for independent evaluation of all potential impacts of such a partnership and calls on those responsible for community health to fully consider the ethical implications of such relationships.

Physical exercise and body-mass index in young adults: a national survey of Norwegian university students

Background

Physical inactivity and obesity pose a major public health challenge. The aim of this study was to describe the level of physical exercise and body-mass index in college and university students, as well as to examine potential changes from 2010 to 2018.

Methods

Data stem from the SHoT study, a national student health survey for higher education in Norway, conducted at 4-year intervals. The SHOT studies conducted so far in 2010, 2014 and 2018, included 6053, 13,525 and 50,054 fulltime students (aged 18–35), respectively. Exercise frequency (average number of times exercising each week) was assessed in all three waves, and was used for the trend analysis. The last wave in 2018 also assessed the average intensity and duration of the exercise.

Results

Overall, students exercised less in 2018 compared to 2014, but comparable to level in 2010. The prevalence of overweight increased substantially from 2010 to 2018, but especially in the last 4 years and among older female students. Less than one of four male, and one of five female students, met the recommended criteria for both exercise frequency, intensity and duration. As expected, the associations between exercise and overweight/obesity were in a dose-response manner, and strong across all three waves.

Conclusions

Our findings show that the large majority of young adults fail to meet international recommendations on exercise, and that the proportion of overweight is increasing in both genders and across all age groups. We conclude that there is an urgent need for a broad approach to achieve a paradigm shift in supporting our college and university students to become more active.

Levels of Physical Activity, Obesity and Related Factors in Young Adults Aged 18-30 during 2009-2017

The objective of this study was to analyze the temporal trend of physical activity and body mass index in young adults aged 18–30 in Spain and to ascertain their relationship with sociodemographic and psychosocial variables in the period of 2009–2017. Methods: A descriptive study with a sample of 10,061 young adults aged 18–30 years was performed. The data were obtained from the European Health Survey in Spain in 2009 and 2014 and the National Health Survey in 2011/2012 and 2017. The chi-square test was used for qualitative variables, and multiple linear regression analysis was performed for physical activity. Results: Sedentary levels had decreased in 2017 as compared to 2011/2012 (p < 0.001); smokers were more sedentary than non-smokers (p < 0.001); men were more active than women (p < 0.001); and the year with the highest physical activity was 2014. Body mass index in the total sample increased from 2009 to 2017 (p < 0.01), showing a significant increase in obesity in women (p < 0.05) and no difference in men (p ≥ 0.05). Conclusions: In the period 2011/2012–2017, the sedentary lifestyle of young adults was reduced and physical activity was increased, with men being more active than women.

Objectively-measured physical activity patterns and longitudinal weight category status in a rural setting

Objectives

To investigate the relationship between longitudinal weight-change and objectively-measured physical activity (PA) in a rural African setting in 143 adults (≥ 30 years), using data from two cross-sectional surveys, separated by approximately 10 years. Participants were categorised into three weight-change groups (Weight-loss: ≥ 25 kg m⁻²→ < 25 kg m⁻²; Weight-gain: < 25 kg m⁻²→ ≥ 25 kg m⁻²; Weight-stability: remained < 25 kg m⁻² or ≥ 25 kg m⁻²). Daily ambulation and activity energy expenditure (AEE), measured in the 2005–2007 health survey, was examined across the weight-change groups. Using the daily AEE data, the proportion of those in the weight-change groups, meeting or not meeting two PA guidelines (150- and 420 min week⁻¹), was examined.

Results

Weight-change was found in 18.2% of the sample. There was no significant overall body mass change (+ 1.2 kg, p = 0.1616). However, there was significant change in body mass in the weight-gain (+ 15.2 kg) and weight-loss (− 10.8 kg) groups (p ≤ 0.0011). Nearly 90% of those who gained weight met the 150 min week⁻¹ guideline. A significantly greater proportion of the weight-stable group (< 25 kg m⁻²) met the 420 min week⁻¹ guideline (p < 0.05). Ambulatory level was high irrespective of weight group, although the weight-stable group (< 25 kg m⁻²) approached 15,000 steps day⁻¹. There was an inconsistent and weak association between PA and weight-change in this group.

On the horizon of aging and physical activity research

This viewpoint is the result of a Horizon Round Table discussion of Exercise and Aging held during the 2017 Saltin International Graduate School in Exercise and Clinical Physiology in Gatineau, Quebec. This expert panel discussed key issues and approaches to future research into aging, across human physiological systems, current societal concerns, and funding approaches. Over the 60-min round table discussion, 3 major themes emerged that the panel considered to be "On the Horizon" of aging research. These themes include (i) aging is a process that extends from womb to tomb; (ii) the importance of longitudinal experimental studies; and (iii) the ongoing need to investigate multiple systems using an integrative approach between scientists, clinicians, and knowledge brokers. With a focus on these themes, we aim to identify critical questions, challenges, and opportunities that face scientists in advancing the understanding of exercise and aging.

Do physical activity, commuting mode, cardiorespiratory fitness and sedentary behaviours modify the genetic predisposition to higher BMI? Findings from a UK Biobank study

OBJECTIVE

To investigate whether the association between a genetic profile risk score for obesity (GPRS-obesity) (based on 93 SNPs) and body mass index (BMI) was modified by physical activity (PA), cardiorespiratory fitness, commuting mode, walking pace and sedentary behaviours.

METHODS

For the analyses we used cross-sectional baseline data from 310,652 participants in the UK Biobank study. We investigated interaction effects of GPRS-obesity with objectively measured and self-reported PA, cardiorespiratory fitness, commuting mode, walking pace, TV viewing, playing computer games, PC-screen time and total sedentary behaviour on BMI. Body mass index (BMI) was the main outcome measure.

RESULTS

GPRS-obesity was associated with BMI (β:0.54 kg.m^-2 per standard deviation (SD) increase in GPRS, [95% CI: 0.53; 0.56]; P = 2.1 × 10^-241). There was a significant interaction between GPRS-obesity and objectively measured PA (P_{[interaction]} = 3.3 × 10^-11): among inactive individuals, BMI was higher by 0.58 kg.m^-2 per SD increase in GPRS-obesity (p = 1.3 × 10^-70) whereas among active individuals the relevant BMI difference was less (β:0.33 kg.m^-2, p = 6.4 × 10^-41). We observed similar patterns for fitness (Unfit β:0.72 versus Fit β:0.36 kg.m^-2, P_{[interaction]} = 1.4 × 10^-11), walking pace (Slow β:0.91 versus Brisk β:0.38 kg.m^-2, P_{[interaction]} = 8.1 × 10^-27), discretionary sedentary behaviour (High β:0.64 versus Low β:0.48 kg.m^-2, P_{[interaction]} = 9.1 × 10^-12), TV viewing (High β:0.62 versus Low β:0.47 kg.m^-2, P_{[interaction]} = 1.7 × 10^-11), PC-screen time (High β:0.82 versus Low β:0.54 kg.m^-2, P_{[interaction]} = 0.0004) and playing computer games (Often β:0.69 versus Low β:0.52 kg.m^-2, P_{[interaction]} = 8.9 × 10^-10). No significant interactions were found for commuting mode (car, public transport, active commuters).

CONCLUSIONS

Physical activity, sedentary behaviours and fitness modify the extent to which a set of the most important known adiposity variants affect BMI. This suggests that the adiposity benefits of high PA and low sedentary behaviour may be particularly important in individuals with high genetic risk for obesity.

Obesity and Urban Environments

Obesity is a major public health issue, affecting both developed and developing societies. Obesity increases the risk for heart disease, stroke, some cancers, and type II diabetes. While individual behaviours are important risk factors, impacts on obesity and overweight of the urban physical and social environment have figured large in the recent epidemiological literature, though evidence is incomplete and from a limited range of countries. Prominent among identified environmental influences are urban layout and sprawl, healthy food access, exercise access, and the neighbourhood social environment. This paper reviews the literature and highlights the special issue contributions within that literature.

What should be the preferred exercise modality for overweight and obese individuals? Protocol for a systematic review and network meta-analysis

BACKGROUND

Obesity is a global epidemic with profound consequences for individuals and societies. Physical exercise is important to weight reduction and weight loss maintenance. However, results on what the most effective type of exercise are unclear. The aim of this systematic review is to evaluate the effects of various exercise modalities with and without caloric restriction on body composition and metabolic health outcomes in overweight and obese adults.

METHODS

We will perform a comprehensive literature search in PubMed, Embase (via Ovid) and CENTRAL (through the Cochrane Library). Relevant papers will be screened in two stages: first, by title and abstract and then the full text of the remaining papers. Two reviewers will screen all the studies, and any disagreements will be discussed with and resolved by a third reviewer. Data extraction and risk of bias assessment will be performed using a pre-piloted form. A network meta-analysis combining direct and indirect treatment effect estimates will be conducted if adequate data are available. The quality of the evidence will be judged using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

DISCUSSION

The results of this proposed systematic review and meta-analysis will identify whether any exercise modality should be preferred for overweight and obese adults, as well as assess the quality of the evidence. This knowledge has potential importance for clinicians and patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019103371.

The Prevalence of Body Mass Index-Associated Chronic Diseases in Diverse Ethnic Groups in New Zealand

The use of universal body mass index (BMI) cutoffs do not take into account variation in the association between BMI and health risk across diverse ethnic groups. We used the New Zealand Health Survey data collected between 2002/2003 and 2014/2015 to calculate the predictive marginal means of hypertension, cardiovascular diseases, and type 2 diabetes mellitus (T2DM) after adjusting for demographic variables and health-related behaviors. Compared with European group, we found that Pacific had a lower prevalence of hypertension at a BMI of ≥35 kg/m², and Māori had a higher prevalence of hypertension, T2DM, and cardiovascular diseases at higher BMI intervals. Whereas Asian had a higher T2DM prevalence compared with Māori, Pacific, and European at some BMI intervals. Using universal BMI cutoffs on the ethnically diverse population to compare obesity rates does not address the risk of chronic diseases associated with high BMI and may stigmatize certain ethnic groups.

Weight-Loss Outcomes from a Pilot Study of African Dance in Older African Americans

OBJECTIVE

Obesity is a risk factor for both cognitive and physical impairment in late adulthood. Though the rates of obesity are high in many groups, older African Americans are disproportionately affected. A randomized pilot intervention of African Dance was conducted with 28 African American older adults with obesity (mean age = 68.4 ± 5.1 years; mean BMI = 33.4 ± 6.2). The goal of the study was to evaluate the physiological outcomes of a culturally sensitive exercise intervention and specifically changes in weight.

METHODS

Participants were randomly assigned to an African Dance (experimental) or Culture Education (control) group. They attended their assigned class for 1 hour per session, 3 days per week, for 6 months.

RESULTS

There was a significant group × time interaction on weight (P  = 0.005) such that the African Dance group lost weight (mean = 4.0 ± 6.0 lb) while the Culture Education group gained weight (mean = 2.6 ± 3.9 lb).

CONCLUSIONS

These results suggest that a culturally sensitive form of physical activity, African Dance, may be effective for promoting weight loss in a population at increased risk for obesity and cognitive decline.

Changes in physical activity over the lifespan: impact on body composition and sarcopenic obesity

Physical activity and body composition show a typical pattern over the lifecycle. Fat-free mass and physical performance generally peak in early adulthood. Here, evidence for a relation between physical activity changes over the life span and the development of sarcopenic obesity is presented. Activity-induced energy expenditure increases with body size and physical activity during growth. The physical activity level, calculated by expressing total energy expenditure as a multiple of resting energy expenditure, gradually increases from early age to adulthood to decrease again in old age. Habitual physical activity has a significant effect on growth of fat-free mass during adolescence and thus on peak fat-free mass and physical performance in early adulthood. Older subjects have a lower fat-free mass and lower physical activity levels but there is no association, suggesting physical activity does not protect against loss of lean body mass at higher age. Prevention of sarcopenic obesity starts with a physically active lifestyle to develop a healthy peak fat-free mass and subsequent prevention of excess fat gain. The change from a physically active to a more sedentary routine in later life requires restriction of energy intake to maintain energy balance.

Physical Activity, Sedentary Time, and Cardiovascular Disease Biomarkers at Age 60 to 64 Years

Background We examined associations of objectively measured physical activity ( PA ) and sedentary time with cardiovascular disease biomarkers at age 60 to 64 years. This included investigation of sex differences and the extent to which associations may be mediated by adiposity. Methods and Results Participants were 795 men and 827 women aged 60 to 64 years from the Medical Research Council National Survey of Health and Development. Combined heart rate and movement sensors worn for 5 consecutive days were used to derive overall PA energy expenditure, kJ /kg per day) and time spent sedentary (<1.5 metabolic equivalent of tasks), in light PA (1.5-3 metabolic equivalent of tasks) and moderate-to-vigorous intensity PA (>3 metabolic equivalent of tasks). Linear regression models were used to relate each PA parameter to inflammatory (C-reactive protein, interleukin-6), endothelial (tissue-plasminogen activator, E-selectin) and adipokine (leptin, adiponectin) markers extracted from fasting blood samples. Greater time in light PA and moderate-to-vigorous intensity PA and less sedentary time were associated with more favorable biomarker levels. For C-reactive protein, interleukin-6, and leptin, these differences were greater among women than men. For example, % differences (95% confidence intervals) in leptin for men and women per SD increases in sedentary time: 7.9 (2.7, 13.0) and 20.6 (15.3, 25.8); light intensity PA : -3.8 (-8.9, 12.7) and -17.7 (-23.1, -12.4), moderate-to-vigorous intensity PA : -12.9 (-17.9, -8.0) and -18.3 (-23.4, -13.1). Fat mass mediated a greater proportion of these associations in women than men. Conclusions Greater light PA and moderate-to-vigorous intensity PA and less sedentary time in early old age were associated with more favorable cardiovascular biomarker profiles. Fat mass partially mediated these associations but more strongly in women than men, which explained sex differences.

Relaxed natural selection contributes to global obesity increase more in males than in females due to more environmental modifications in female body mass

OBJECTIVE

Relaxed natural selection, measured by Biological State Index (Ibs), results in unfavourable genes/mutations accumulation in population. Obesity is partly heritable. We aim to examine and compare the effects of relaxed natural selection on male and female obesity prevalence.

METHODS

Data for 191 countries of the world were captured for this ecological study. Curvilinear regressions, bivariate and partial correlations, linear mixed models and multivariate linear regression analyses were used to examine the relationship between Ibs and sex-specific obesity prevalence. Per capita GDP, urbanization and caloric intake were controlled for as the confounding factors. Fisher r-to-z transformation, R2 increment in multivariate regression and F-test were used to compare the correlations.

RESULTS

Curvilinear regressions, bivariate and partial correlations (controlled for GDP, urbanization and calories) revealed that Ibs was significantly correlated to obesity prevalence of both sexes, but significantly stronger to male than to female obesity prevalence. Curvilinear regression models also showed strong correlations. Mixed linear models, with effects of GDP, urbanisation and caloric intake controlled for, showed that male and female average obesity prevalence rates were significantly higher in countries with greater Ibs value than their equivalents in countries with lower Ibs. Between higher and lower Ibs countries, the gap of male obesity prevalence is 60% greater than the gap of female obesity prevalence. Stepwise multiple regression identified that Ibs was a significant predictor of obesity prevalence of both sexes. Multivariate regression showed that, adding Ibs as an obesity predictor, R2 increment in male model was significantly greater than in female model.

CONCLUSIONS

Relaxed natural selection may drive males and females to accumulate metabolic faulty genes equally. Probably due to greater environmental, personal intervention in regulating female body mass, relaxed natural selection shows less contributing effects to female obesity prevalence than to male obesity prevalence. Gene therapy to prevent obesity may need to be also taken into account.

Generational differences in patterns of physical activities over time in the Canadian population: an age-period-cohort analysis

Background

Using longitudinal panel data, the aim of this study was to examine the contribution of age, period, and cohort effects on changes in physical activity over time in a population-based sample of Canadians. We focused on three domains of physical activities: leisure time, commuting (i.e. walking and cycling), and daily activities (i.e. sedentary behavior). We also examined whether changes in sedentary behavior related to changes in participation in leisure time and commuting activities.

Methods

We used data from the Longitudinal National Population Health Survey (1994–2011): 10050 participants born between 1935 and 1984 grouped in five 10-years birth cohorts. We examined three outcomes: moderate-to-vigorous leisure time physical activity, active commuting, and sedentary behavior. We also included education, income, and body mass index as covariates. We used hierarchical age-period-cohort analysis to examine the contribution of age, period, and cohort effects to changes over time for each outcome.

Results

We found that recent cohorts were more likely to report sedentary behavior and greater participation in leisure time physical activities and active commuting. We also found a significant trend of increasing participation in active leisure time physical activity and active commuting among Canadians from 1994/95 to 2010/11 and, at the same time, an increase in sedentary behavior. The greater participation in leisure time physical activities and active commuting in each succeeding recent cohort was partially related to the secular trend of increasing participation in physical activities over time in the population. Furthermore, those with sedentary behavior were less likely to report participation in physical activities. Overall, obese individuals were less likely to be physically active and more likely to be sedentary, while the effect of socio-economic status varied by outcome.

Conclusions

The greater participation in physical activities (leisure time and commuting) in recent cohorts is encouraging and was substantially explained by period effects, which reflect broad social and environmental factors affecting the whole population. The large cohort effect of increasing sedentary behavior and the inverse relationship between sedentary behavior and physical activity is concerning, and identifies a target group for future interventions.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5189-z) contains supplementary material, which is available to authorized users.

Determinants of body mass index by gender in the Dikgale Health and Demographic Surveillance System site, South Africa

BACKGROUND

The study was conducted in the Dikgale Health and Demographic Surveillance System (DHDSS) site where we have observed increasing obesity levels, particularly in women, despite evidence of high physical activity (PA) and a relatively low daily energy intake.

OBJECTIVE

This study aimed to assess the socio-demographic, behavioural and biological determinants of body mass index (BMI) in adult residents permanently residing in the DHDSS.

METHODS

A cross-sectional study was conducted in which socio-demographic, behavioural and biological characteristics from 1143 participants (aged 40-60 years) were collected using a paper questionnaire and standard anthropometric measures. Human immunodeficiency virus (HIV) testing was performed on all participants except those who indicated that they had tested positive. Chi-square and Mann-Whitney tests were used to analyze categorical and continuous variables, respectively, while hierarchical multivariate regression was used to analyze predictors of BMI.

RESULTS

The median age of women and men was 51 (46-56) and 50 (45-55) years, respectively. The prevalence of overweight-obesity was 76% in women and 21% in men. A significant negative association of BMI with HIV and smoking and a significant positive association with socio-economic status (SES) was observed in both sexes. In women, BMI was negatively associated with sleep duration (p = 0.015) and age (p = 0.012), but positively associated with sugar-sweetened beverages (SSBs) (p = 0.08). In men, BMI was negatively associated with alcohol use (p = 0.016) and positively associated with being married (p < 0.001). PA was not associated with BMI in either sexes. Full models explained 9.2% and 20% of the variance in BMI in women and men, respectively.

CONCLUSION

BMI in DHDSS adults is not associated with physical inactivity but is associated wealth, marital status, sleep, smoking, alcohol use, and HIV status. Future studies should explore the contribution of nutrition, stunting, psycho-social and genetic factors to overweight and obesity in DHDSS.

Socio-Behavioral Factors Associated with Overweight and Central Obesity in Tehranian Adults: a Structural Equation Model

PURPOSE

This study aimed to test a conceptual model of associations between socio-demographic and behavioral factors and obesity in the Tehran Lipid and Glucose Study (TLGS).

METHODS

Data from 2747 TLGS adult participants (58.3 % female) were analyzed. Socio-demographic and behavioral factors in the conceptual model were tested for their direct and indirect associations with overweight and central obesity, using structural equation modeling (SEM), conducted by IBM SPSS AMOS software.

RESULTS

Overweight and central obesity were found in 61.6 and 48.1 % of respondents, respectively. Fit indices were acceptable for the conceptual model. Daily energy intake had a direct association with overweight and central obesity in both genders; however, poor dietary pattern had direct associations with overweight and central obesity only in men. In women, age, marital status, and level of education had direct associations with overweight and central obesity. In men, only age and marital status had direct associations with overweight and central obesity.

CONCLUSIONS

Age and marital status in both genders and level of education only in women were among the socio-demographic factors which were directly associated with both overweight and central obesity. Among behavioral factors, daily energy intake was the most important factor that was directly associated with both overweight and central obesity in both genders. Adherence to poor diet directly was associated with overweight and central obesity only in men. The current findings provide beneficial information for designing culturally relevant and effective interventions/strategies for prevention of overweight among Tehranian adults.

The Prevalence of Overfat Adults and Children in the US

The overfat condition is defined as excess body fat sufficient to impair health. The problem exists in most overweight and obese individuals and can also occur in those who are normal-weight and non-obese, often due to excess abdominal fat. Despite previous indications that the prevalence overweight and obesity is leveling, these conditions are currently at their highest levels in US history. Our review estimated the number of overfat Americans at 91% for adults and 69% for children. The primary purpose of this review was to build upon previous estimations of overfat prevalence in developed countries by using new data from the Centers for Disease Control and Prevention to estimate the overfat prevalence in American adults (≥20 years) and children (2-19 years), and to expand the definition of overfat as excess body fat associated with at least one additional risk factor of impaired cardiometabolic or physical health. The secondary goals are to highlight the role of dietary sugar as a primary cause of the overfat pandemic and mention new data showing the increased prevalence of exercise that parallels the rising prevalence of overfat to further emphasize the secondary role exercise may play in fat loss. Current public health guidelines to address the overfat pandemic may require more emphasis on reducing the consumption of refined carbohydrates, including added sugars.

A casein hydrolysate based formulation attenuates obesity and associated non-alcoholic fatty liver disease and atherosclerosis in LDLr-/-.Leiden mice

Background

Obesity frequently associates with the development of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis. Chronic inflammation in white adipose tissue (WAT) seems to be an important driver of these manifestations.

Objective

This study investigated a combination of an extensively hydrolyzed casein (eHC), docosahexaenoic acid (DHA), arachidonic acid (ARA), and Lactobacillus Rhamnosus GG (LGG) (together referred to as nutritional ingredients, NI) on the development of obesity, metabolic risk factors, WAT inflammation, NAFLD and atherosclerosis in high-fat diet-fed LDLr-/-.Leiden mice, a model that mimics disease development in humans.

Methods

LDLr-/-.Leiden male mice (n = 15/group) received a high-fat diet (HFD, 45 Kcal%) for 21 weeks with or without the NI (23.7% eHC, 0.083% DHA, 0.166% ARA; all w/w and 1x10⁹ CFU LGG gavage 3 times/week). HFD and HFD+NI diets were isocaloric. A low fat diet (LFD, 10 Kcal%) was used for reference. Body weight, food intake and metabolic risk factors were assessed over time. At week 21, tissues were analyzed for WAT inflammation (crown-like structures), NAFLD and atherosclerosis. Effects of the individual NI components were explored in a follow-up experiment (n = 7/group).

Results

When compared to HFD control, treatment with the NI strongly reduced body weight to levels of the LFD group, and significantly lowered (P<0.01) plasma insulin, cholesterol, triglycerides, leptin and serum amyloid A (P<0.01). NI also reduced WAT mass and inflammation. Strikingly, NI treatment significantly reduced macrovesicular steatosis, lobular inflammation and liver collagen (P<0.05), and attenuated atherosclerosis development (P<0.01). Of the individual components, the effects of eHC were most pronounced but could not explain the entire effects of the NI formulation.

Conclusions

A combination of eHC, ARA, DHA and LGG attenuates obesity and associated cardiometabolic diseases (NAFLD, atherosclerosis) in LDLr-/-.Leiden mice. The observed reduction of inflammation in adipose tissue and in the liver provides a rationale for these comprehensive health effects.

A brief review of salient factors influencing adult eating behaviour

A better understanding of the factors that influence eating behaviour is of importance as our food choices are associated with the risk of developing chronic diseases such as obesity, CVD, type 2 diabetes or some forms of cancer. In addition, accumulating evidence suggests that the industrial food production system is a major contributor to greenhouse gas emission and may be unsustainable. Therefore, our food choices may also contribute to climate change. By identifying the factors that influence eating behaviour new interventions may be developed, at the individual or population level, to modify eating behaviour and contribute to society’s health and environmental goals. Research indicates that eating behaviour is dictated by a complex interaction between physiology, environment, psychology, culture, socio-economics and genetics that is not fully understood. While a growing body of research has identified how several single factors influence eating behaviour, a better understanding of how these factors interact is required to facilitate the developing new models of eating behaviour. Due to the diversity of influences on eating behaviour this would probably necessitate a greater focus on multi-disciplinary research. In the present review, the influence of several salient physiological and environmental factors (largely related to food characteristics) on meal initiation, satiation (meal size) and satiety (inter-meal interval) are briefly discussed. Due to the large literature this review is not exhaustive but illustrates the complexity of eating behaviour. The present review will also highlight several limitations that apply to eating behaviour research.

Attenuating the Biologic Drive for Weight Regain Following Weight Loss: Must What Goes Down Always Go Back Up?

Metabolic adaptations occur with weight loss that result in increased hunger with discordant simultaneous reductions in energy requirements—producing the so-called energy gap in which more energy is desired than is required. The increased hunger is associated with elevation of the orexigenic hormone ghrelin and decrements in anorexigenic hormones. The lower total daily energy expenditure with diet-induced weight loss results from (1) a disproportionately greater decrease in circulating leptin and resting metabolic rate (RMR) than would be predicted based on the decline in body mass, (2) decreased thermic effect of food (TEF), and (3) increased energy efficiency at work intensities characteristic of activities of daily living. These metabolic adaptations can readily promote weight regain. While more experimental research is needed to identify effective strategies to narrow the energy gap and attenuate weight regain, some factors contributing to long-term weight loss maintenance have been identified. Less hunger and greater satiation have been associated with higher intakes of protein and dietary fiber, and lower glycemic load diets. High levels of physical activity are characteristic of most successful weight maintainers. A high energy flux state characterized by high daily energy expenditure and matching energy intake may attenuate the declines in RMR and TEF, and may also result in more accurate regulation of energy intake to match daily energy expenditure.

Body-Brain Connections: The Effects of Obesity and Behavioral Interventions on Neurocognitive Aging

Obesity is a growing public health problem in the United States, particularly in middle-aged and older adults. Although the key factors leading to a population increase in body weight are still under investigation, there is evidence that certain behavioral interventions can mitigate the negative cognitive and brain ("neurocognitive") health consequences of obesity. The two primary behaviors most often targeted for weight loss are caloric intake and physical activity. These behaviors might have independent, as well as overlapping/synergistic effects on neurocognitive health. To date obesity is often described independently from behavioral interventions in regards to neurocognitive outcomes, yet there is conceptual and mechanistic overlap between these constructs. This review summarizes evidence linking obesity and modifiable behaviors, such as physical activity and diet, with brain morphology (e.g., gray and white matter volume and integrity), brain function (e.g., functional activation and connectivity), and cognitive function across the adult lifespan. In particular, we review evidence bearing on the following question: Are associations between obesity and brain health in aging adults modifiable by behavioral interventions?

Obesity in Low- and Middle-Income Countries: Burden, Drivers, and Emerging Challenges

We have reviewed the distinctive features of excess weight, its causes, and related prevention and management efforts, as well as data gaps and recommendations for future research in low- and middle-income countries (LMICs). Obesity is rising in every region of the world, and no country has been successful at reversing the epidemic once it has begun. In LMICs, overweight is higher in women compared with men, in urban compared with rural settings, and in older compared with younger individuals; however, the urban–rural overweight differential is shrinking in many countries. Overweight occurs alongside persistent burdens of underweight in LMICs, especially in young women. Changes in the global diet and physical activity are among the hypothesized leading contributors to obesity. Emerging risk factors include environmental contaminants, chronic psychosocial stress, neuroendocrine dysregulation, and genetic/epigenetic mechanisms. Data on effective strategies to prevent the onset of obesity in LMICs or elsewhere are limited. Expanding the research in this area is a key priority and has important possibilities for reverse innovation that may also inform interventions in high-income countries.

Longitudinal associations between body mass index, physical activity, and healthy dietary behaviors in adults: A parallel latent growth curve modeling approach

Background

Physical activity (PA) and healthy dietary behaviors (HDB) are two well-documented lifestyle factors influencing body mass index (BMI). This study examined 7-year longitudinal associations between changes in PA, HDB, and BMI among adults using a parallel latent growth curve modeling (LGCM).

Methods

We used prospective cohort data collected by a private company (SimplyWell LLC, Omaha, NE, USA) implementing a workplace health screening program. Data from a total of 2,579 adults who provided valid BMI, PA, and HDB information for at least 5 out of 7 follow-up years from the time they entered the program were analyzed. PA and HDB were subjectively measured during an annual online health survey. Height and weight measured during an annual onsite health screening were used to calculate BMI (kg·m²). The parallel LGCMs stratified by gender and baseline weight status (normal: BMI<25, overweight BMI 25–29.9, and obese: BMI>30) were fitted to examine the longitudinal associations of changes in PA and HDB with change in BMI over years.

Results

On average, BMI gradually increased over years, at rates ranging from 0.06 to 0.20 kg·m²·year, with larger increases observed among those of normal baseline weight status across genders. The increases in PA and HDB were independently associated with a smaller increase in BMI for obese males (b = -1.70 and -1.98, respectively), and overweight females (b = -1.85 and -2.46, respectively) and obese females (b = -2.78 and -3.08, respectively). However, no significant associations of baseline PA and HDB with changes in BMI were observed.

Conclusions

Our study suggests that gradual increases in PA and HDB are independently associated with smaller increases in BMI in overweight and obese adults, but not in normal weight individuals. Further study is warranted to address factors that check increases in BMI in normal weight adults.