Child and adolescent obesity: part of a bigger picture

Obesity-promoting factors in Mexican children and adolescents: challenges and opportunities

BACKGROUND

Mexico is a developing country with one of the highest youth obesity rates worldwide; >34% of children and adolescents between 5 and 19 years of age are overweight or obese.

OBJECTIVES

The current review seeks to compile, describe, and analyze dietary conditions, physical activity, socioeconomic status, and cultural factors that create and exacerbate an obesogenic environment among Mexican youth.

DESIGN

A narrative review was performed using PubMed and the Cochrane Library databases, as well as grey literature data from the Mexican government, academics, and statistical reports from nongovernmental organizations, included in electronic formats.

RESULTS

The recent socioeconomic and nutritional transition has resulted in reduced healthy meal options at public schools, high rates of sedentary lifestyles among adolescents, lack of open spaces and playgrounds, socioeconomic deprivation, false or misunderstood sociocultural traditional beliefs, misconceptions about health, a high percentage of overweight or obese adults, and low rates of maternal breastfeeding. Some of the factors identified are exacerbating the obesity problem in this population. Current evidence also shows that more policies and health programs are needed for prevention of childhood and adolescent obesity. Mexico presents alarming obesity levels, which need to be curtailed and urgently reversed.

CONCLUSIONS

The present narrative review presents an overview of dietary, physical activity, societal and cultural preconceptions that are potentially modifiable obesity-promoting factors in Mexican youth. Measures to control these factors need to be implemented in all similar developing countries by governments, policy makers, stakeholders, and health care professionals to tackle obesity in children and young people.

Biological, environmental, and social influences on childhood obesity

The prevalence of childhood obesity has increased globally over the past three decades, with evidence of recent leveling off in developed countries. Reduction in the, currently high, prevalence of obesity will require a full understanding of the biological and social pathways to obesity in order to develop appropriately targeted prevention strategies in early life. Determinants of childhood obesity include individual level factors, including biological, social, and behavioral risks, acting within the influence of the child's family environment, which is, in turn, imbedded in the context of the community environment. These influences act across childhood, with suggestions of early critical periods of biological and behavioral plasticity. There is evidence of sex and gender differences in the responses of boys and girls to their environments. The evidence that determinants of childhood obesity act at many levels and at different stages of childhood is of policy relevance to those planning early health promotion and primary prevention programs as it suggests the need to address the individual, the family, the physical environment, the social environment, and social policy. The purpose of this narrative review is to summarize current, and emerging, literature in a multilevel, life course framework.

Plyometric exercise combined with high-intensity interval training improves metabolic abnormalities in young obese females more so than interval training alone

The aim of this study was to compare the effects of 12 weeks of high-intensity interval training (HIIT) with the effects of 12 weeks of plyometric exercise combined with HIIT (P+HIIT) on anthropometric, biochemical, and physical fitness data in young obese females. Sixty-eight participants (age, 16.6 ± 1.3 y; body mass, 82.8 ± 5.0 kg; body fat, 39.4% ± 3.3%; body mass index z score, 2.9 ± 0.4) were assigned to 1 of 3 groups: HIIT (2 blocks per session of 6–8 bouts of 30-s runs at 100% velocity at peak oxygen uptake, with 30-s active recovery between bouts at 50%velocity at peak oxygen uptake (n = 23)); P+HIIT (2 blocks per session of 3 different 15-s plyometric exercises with 15-s passive recoveries, totaling 2 min for each plyometric exercise + the same HIIT program (n = 26)); or control (no exercise (n = 19)). Anthropometric (body mass, body mass index z score, body fat, lean body mass, and waist circumference), biochemical (plasma glucose, insulin, leptin and adiponectin concentrations, leptin/adiponectin ratio, and homeostasis model assessment of insulin resistance (HOMA-IR)), physical fitness (peak oxygen uptake, velocity at peak oxygen uptake, squat jump, and countermovement jump performances), and energy intake data were collected. Both training programs improved the anthropometric, biochemical, and physical fitness variables. However, the P+HIIT program induced greater improvements than did the HIIT program in lean body mass (+3.0% ± 1.7%), plasma glucose and leptin concentrations (–11.0% ± 4.7% and –23.8% ± 5.8%, respectively), plasma leptin/adiponectin ratio (–40.9% ± 10.9%), HOMA-IR (–37.3% ± 6.2%), and squat jump performance (22.2% ± 7.5%). Taken together, these findings suggest that adding plyometric exercises to a HIIT program may be more beneficial than HIIT alone in obese female adolescents.

Active Living: development and quasi-experimental evaluation of a school-centered physical activity intervention for primary school children

Background

The worldwide increase in the rates of childhood overweight and physical inactivity requires successful prevention and intervention programs for children. The aim of the Active Living project is to increase physical activity and decrease sedentary behavior of Dutch primary school children by developing and implementing tailored, multicomponent interventions at and around schools.

Methods/design

In this project, school-centered interventions have been developed at 10 schools in the south of the Netherlands, using a combined top-down and bottom-up approach in which a research unit and a practice unit continuously interact. The interventions consist of a combination of physical and social interventions tailored to local needs of intervention schools. The process and short- and long-term effectiveness of the interventions will be evaluated using a quasi-experimental study design in which 10 intervention schools are matched with 10 control schools. Baseline and follow-up measurements (after 12 and 24 months) have been conducted in grades 6 and 7 and included accelerometry, GPS, and questionnaires. Primary outcome of the Active Living study is the change in physical activity levels, i.e. sedentary behavior (SB), light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and counts-per-minute (CPM). Multilevel regression analyses will be used to assess the effectiveness of isolated and combined physical and social interventions on children’s PA levels.

Discussion

The current intervention study is unique in its combined approach of physical and social environmental PA interventions both at school(yard)s as well as in the local neighborhood around the schools. The strength of the study lies in the quasi-experimental design including objective measurement techniques, i.e. accelerometry and GPS, combined with more subjective techniques, i.e. questionnaires, implementation logbooks, and neighborhood observations.

Trial registration

Current Controlled Trials ISRCTN25497687 (registration date 21/10/2015), METC 12-4-077, Project number 200130003

Nutrition and the science of disease prevention: a systems approach to support metabolic health

Progress in nutritional science, genetics, computer science, and behavioral economics can be leveraged to address the challenge of noncommunicable disease. This report highlights the connection between nutrition and the complex science of preventing disease and discusses the promotion of optimal metabolic health, building on input from several complementary disciplines. The discussion focuses on (1) the basic science of optimal metabolic health, including data from gene-diet interactions, microbiome, and epidemiological research in nutrition, with the goal of defining better targets and interventions, and (2) how nutrition, from pharma to lifestyle, can build on systems science to address complex issues.

Promoting healthful family meals to prevent obesity: HOME Plus, a randomized controlled trial

Background

Family meal frequency has been shown to be strongly associated with better dietary intake; however, associations with weight status have been mixed. Family meals-focused randomized controlled trials with weight outcomes have not been previously conducted. Therefore, this study purpose was to describe weight-related outcomes of the HOME Plus study, the first family meals-focused randomized controlled trial to prevent excess weight gain among youth.

Methods

Families (n = 160 8-12-year-old children and their parents/guardians) were randomized to intervention (n = 81) or control (n = 79) groups. Data were collected at baseline (2011–2012), post-intervention (12-months post-baseline) and follow-up (21-months post-baseline). The intervention included ten monthly group sessions (nutrition education; hands-on meal and snack planning, preparation, and skill development; screen time reductions) and five motivational, goal-setting phone calls. The main outcome was child body mass index (BMI) z-score.

Results

General linear models, adjusted for baseline values and demographics, showed no significant treatment group differences in BMI z-scores at post-intervention or follow-up; however, a promising reduction in excess weight gain was observed. Post-hoc stratification by pubertal onset indicated prepubescent children in the intervention group had significantly lower BMI z-scores than their control group counterparts.

Conclusions

The study used a strong theoretical framework, rigorous design, quality measurement and a program with high fidelity to test a family meals-focused obesity prevention intervention. It showed a modest decrease in excess weight gain. The significant intervention effect among prepubescent children suggests the intervention may be more efficacious among relatively young children, although more research with appropriately powered samples are needed to replicate this finding.

Trial registration

This study is registered at www.clinicaltrials.gov NCT01538615. Registered 01/17/2012.

An international comparison of dietary patterns in 9-11-year-old children

OBJECTIVES

Dietary pattern is defined as a combination of foods and drinks and the frequency of consumption within a population. Dietary patterns are changing on a global level, which may be linked to an increased incidence of chronic diseases. The aim of this study was to identify and compare the dietary patterns among 9-11-year-old children living in urban regions in different parts of the world.

METHODS

Participants were 7199 children (54% girls), aged 9-11 years, from 12 countries situated in all major world regions. Food consumption was assessed using a 23-item Food Frequency Questionnaire (FFQ). To identify dietary patterns, principal components analyses (PCA) were carried out using weekly portions as input variables.

RESULTS

Both site-specific and pooled PCA resulted in two strong components. Component 1 ('unhealthy diet pattern') included fast foods, ice cream, fried food, French fries, potato chips, cakes and sugar-sweetened sodas with >0.6 loadings. The loadings for component 2 ('healthy diet pattern') were slightly weaker with only dark-green vegetables, orange vegetables, vegetables in general, and fruits and berries reaching a >0.6 loading. The site-specific diet pattern scores had very strong correlations with the pattern scores from the pooled data: r=0.82 and 0.94 for components 1 and 2, respectively.

CONCULSIONS

The results suggest that the same 'healthier' and 'unhealthier' foods tend to be consumed in similar combinations among 9-11-year-old children in different countries, despite variation in food culture, geographical location, ethnic background and economic development.

Association between home and school food environments and dietary patterns among 9-11-year-old children in 12 countries

OBJECTIVES

We investigated the roles of home and school environments on dietary patterns among children from 12 countries differing widely in geographic region and levels of human and economic development.

METHODS

The sample included a total of 6685 (54% girls) 9-11-year-old children. Parents/guardians reported the availability of certain foods in the home, and trained researchers performed school audits recording the availability of foods for sale at schools. Foods were then divided into wholesome (nutrient-dense) and empty-calorie (nutrient-poor) foods and scored according to their availability. Children reported if their school provided school lunch and how many times during the last week they had eaten meals prepared away from home and school. Via principal components analysis, data-driven dietary pattern scores were calculated from food frequency questionnaires. Multilevel models were used to study the associations between home and school food environments (wholesome and empty-calorie foods) and dietary patterns (healthy and unhealthy diet pattern scores).

RESULTS

For low unhealthy diet pattern scores, low availability of empty-calorie foods at home was found to be more important than high availability of wholesome foods. More meals eaten outside home and school were associated with the higher unhealthy diet pattern scores. The availability of wholesome foods at home was positively associated with the healthy diet pattern scores. Food availability at school was not associated with the dietary patterns.

CONCLUSIONS

In this sample, the home food environment was more significant than the school food environment in predicting the dietary patterns. The availability of empty-calorie foods was associated with the unhealthy dietary pattern even when the availability of wholesome foods at home was high. Meals prepared away from home contributed to the unhealthy dietary pattern. Therefore, parents should be encouraged to limit the availability of empty-calorie foods and eating outside the home.

Relationships between active school transport and adiposity indicators in school-age children from low-, middle- and high-income countries

OBJECTIVES

Within the global context of the nutrition and physical activity transition it is important to determine the relationship between adiposity and active school transport (AST) across different environmental and socio-cultural settings. The present study assessed the association between adiposity (that is, body mass index z-score (BMIz), obesity, percentage body fat (PBF), waist circumference) and AST in 12 country sites, in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE).

METHODS

The analytical sample included 6797 children aged 9-11 years. Adiposity indicators included, BMIz calculated using reference data from the World Health Organization, obesity (BMIz ⩾+2 s.d.), PBF measured using bioelectrical impedance and waist circumference. School travel mode was assessed by questionnaire and categorized as active travel versus motorized travel. Multilevel linear and non-linear models were used to estimate the magnitude of the associations between adiposity indicators and AST by country site and sex.

RESULTS

After adjusting for age, sex, parental education and motorized vehicle availability, children who reported AST were less likely to be obese (odds ratio=0.72, 95% confidence interval (0.60-0.87), P<0.001) and had a lower BMIz (-0.09, s.e.m.=0.04, P=0.013), PBF (least square means (LSM) 20.57 versus 21.23% difference -0.66, s.e.m.=0.22, P=0.002) and waist circumference (LSM 63.73 cm versus 64.63 cm difference -0.90, s.e.m.=0.26, P=0.001) compared with those who reported motorized travel. Overall, associations between obesity and AST did not differ by country (P=0.279) or by sex (P=0.571).

CONCLUSIONS

AST was associated with lower measures of adiposity in this multinational sample of children. Such findings could inform global efforts to prevent obesity among school-age children.

Change in Metabolic Profile after 1-Year Nutritional-Behavioral Intervention in Obese Children

Research findings are inconsistent about improvement of specific cardio-metabolic variables after lifestyle intervention in obese children. The aim of this trial was to evaluate the effect of a 1-year intervention, based on normocaloric diet and physical activity, on body mass index (BMI), blood lipid profile, glucose metabolism and metabolic syndrome. Eighty-five obese children aged ≥6 years were analyzed. The BMI z-score was calculated. Fasting blood samples were analyzed for lipids, insulin and glucose. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated and insulin resistance was defined as HOMA-IR >3.16. HOMA-β%, quantitative insulin sensitivity check index and triglyceride glucose index were calculated. The metabolic syndrome was defined in accordance with the International Diabetes Federation criteria. At the end of intervention children showed a reduction (mean (95% CI)) in BMI z-score (-0.58 (-0.66; -0.50)), triglycerides (-0.35 (-0.45; -0.25) mmol/L) and triglyceride glucose index (-0.29 (-0.37; -0.21)), and an increase in HDL cholesterol (0.06 (0.01; 0.11) mmol/L). Prevalence of insulin resistance declined from 51.8% to 36.5% and prevalence of metabolic syndrome from 17.1% to 4.9%. Nutritional-behavioral interventions can improve the blood lipid profile and insulin sensitivity in obese children, and possibly provide benefits in terms of metabolic syndrome.

Caloric restriction and exercise "mimetics'': Ready for prime time?

Exercise and diet are powerful interventions to prevent and ameliorate various pathologies. The development of pharmacological agents that confer exercise- or caloric restriction-like phenotypic effects is thus an appealing therapeutic strategy in diseases or even when used as life-style and longevity drugs. Such so-called exercise or caloric restriction "mimetics" have so far mostly been described in pre-clinical, experimental settings with limited translation into humans. Interestingly, many of these compounds activate related signaling pathways, most often postulated to act on the common downstream effector peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in skeletal muscle. In this review, resveratrol and other exercise- and caloric restriction "mimetics" are discussed with a special focus on feasibility, chances and limitations of using such compounds in patients as well as in healthy individuals.

Linking obesogenic dysregulation to prostate cancer progression

The global epidemic of obesity is closely linked to the development of serious co-morbidities, including many forms of cancer. Epidemiological evidence consistently shows that obesity is associated with a similar or mildly increased incidence of prostate cancer but, more prominently, an increased risk for aggressive prostate cancer and prostate cancer-specific mortality. Studies in mice demonstrate that obesity induced by high-fat feeding increases prostate cancer progression; however, the mechanisms underpinning this relationship remain incompletely understood. Adipose tissue expansion in obesity leads to local tissue dysfunction and is associated with low-grade inflammation, alterations in endocrine function and changes in lipolysis that result in increased delivery of fatty acids to tissues of the body. The human prostate gland is covered anteriorly by the prominent peri-prostatic adipose tissue and laterally by smaller adipose tissue depots that lie directly adjacent to the prostatic surface. We discuss how the close association between dysfunctional adipose tissue and prostate epithelial cells might result in bi-directional communication to cause increased prostate cancer aggressiveness and progression. However, the literature indicates that several 'mainstream' hypotheses regarding obesity-related drivers of prostate cancer progression are not yet supported by a solid evidence base and, in particular, are not supported by experiments using human tissue. Understanding the links between obesity and prostate cancer will have major implications for the health policy for men with prostate cancer and the development of new therapeutic or preventative strategies.

Should the IDEFICS outcomes have been expected?

The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study evaluated with a large sample a comprehensive carefully planned obesity prevention intervention targeting multiple levels of influence that were culturally adapted to the situations in eight European countries. Despite the great effort and attention to detail, the IDEFICS study did not achieve its targeted adiposity or behaviour change objectives. Should we be surprised that the IDEFICS trial did not have its intended effects? We think not, and would have been surprised if it did. Recent research has revealed the lack of consistent meaningful relationships between several apparently obesogenic behaviours and adiposity, weak or no relationships among behavioural change procedures, mediating variables and targeted behaviours and inadequate attention to moderating effects. Future obesity prevention interventions would benefit from a more thorough understanding of the complex relationships that have been hypothesized and the interrelationships with biological factors. While systems modelling has been proposed as providing the solution, important less complex identification of new constructs, new relationships and community interventions are still needed, both to find innovative solutions and to provide input into the systems models. We should question results from cross-sectional studies and be satisfied only with longitudinal or experimental tests of relationships.

Associations between Sleep Duration and Overweight/Obesity: Results from 66,817 Chinese Adolescents

The findings about the shapes of associations between sleep duration and overweight/obesity in adolescents were largely inconsistent in the existing literature. We examined the functional forms of the associations between sleep duration and overweight/obesity in 66,817 Chinese adolescents by modelling sleep duration categorically and continuously. The adjusted ORs (95% CI) of overweight (with 7.0–8.9 h of sleep being considered the reference group) for subjects reporting <5.0 hours, 5.0–6.9 hours and ≥9.0 hours of sleep were 1.26 (1.05–1.51), 1.06 (1.00–1.11) and 1.27 (1.14–1.42), respectively. The adjusted ORs (95% CI) of obesity (with 7.0–8.9 h of daily sleep being considered as the reference group) for adolescents reporting <5.0 hours, 5.0–6.9 hours and ≥9.0 hours of sleep were 1.24 (0.97–1.57), 0.94 (0.87–1.01) and 1.42 (1.24–1.63), respectively. Continuous splines regressions support non-linear U shape associations between sleep duration and overweight/obesity, with the bottom at around 7.0–8.0 hours sleep (overweight: likelihood ratio = 32.7 p < 0.01; obesity: likelihood ratio = 40.4 p < 0.01). U-shape associations were found between sleep duration and overweight/obesity in Chinese adolescents and an optimal sleep duration of 7.0–8.0 hours sleep may prevent overweight/obesity.

Overweight and Obesity and Associated Factors among School-Aged Adolescents in Six Pacific Island Countries in Oceania

The aim of this study was to assess overweight and obesity and associated factors in school-going adolescents in six Pacific Island countries in Oceania. The sample included 10,424 school-going adolescents predominantly 13–16 years old from Fiji, Kiribati, Samoa, Solomon Islands, Tonga, and Vanuatu. Bivariate and multivariable analyses were conducted to assess the relationship between dietary behaviour, substance use, physical activity, psychosocial factors, social-familial influences, and overweight or obesity. The prevalence of overweight and obesity was determined based on self-reported height and weight and the international child body mass index standards. Results indicate a prevalence of overweight or obesity of 24.3% and obesity of 6.1% in the six countries, ranging in terms of overweight or obesity and obesity from 12.0% and 0.4% in Vanuatu to 58.7% and 21.1% in Tonga, respectively. In multivariable regression analysis, being female was associated with overweight, carbonated soft drink use with obesity, sedentary behaviour with overweight or obesity, suicidal ideation with overweight, having close friends and peer support with overweight and obesity, parental or guardian supervision with overweight, and parental or guardian bonding was associated with overweight or obesity. High prevalence rates of overweight and obesity were found and several factors identified which can help guide interventions.

Updated prevalence rates of overweight and obesity in 11- to 17-year-old adolescents in Germany. Results from the telephone-based KiGGS Wave 1 after correction for bias in self-reports

Background

The nationwide “German Health Interview and Examination Survey for Children and Adolescents” (KiGGS), conducted in 2003–2006, showed an increase in the prevalence rates of overweight and obesity compared to the early 1990s, indicating the need for regularly monitoring. Recently, a follow-up—KiGGS Wave 1 (2009–2012)—was carried out as a telephone-based survey, providing self-reported height and weight. Since self-reports lead to a bias in prevalence rates of weight status, a correction is needed. The aim of the present study is to obtain updated prevalence rates for overweight and obesity for 11- to 17-year olds living in Germany after correction for bias in self-reports.

Methods

In KiGGS Wave 1, self-reported height and weight were collected from 4948 adolescents during a telephone interview. Participants were also asked about their body perception. From a subsample of KiGGS Wave 1 participants, measurements for height and weight were collected in a physical examination. In order to correct prevalence rates derived from self-reports, weight status categories based on self-reported and measured height and weight were used to estimate a correction formula according to an established procedure under consideration of body perception. The correction procedure was applied and corrected rates were estimated.

Results

The corrected prevalence of overweight, including obesity, derived from KiGGS Wave 1, showed that the rate has not further increased compared to the KiGGS baseline survey (18.9 % vs. 18.8 % based on the German reference).

Conclusion

The rates of overweight still remain at a high level. The results of KiGGS Wave 1 emphasise the significance of this health issue and the need for prevention of overweight and obesity in children and adolescents.

Caring for children with NAFLD and navigating their care into adulthood

NAFLD is the most common chronic liver disease in children and adults, with its prevalence closely associated with obesity and other features of the metabolic syndrome. As young adults with NAFLD transition from the paediatric care environment to adult services, establishing a coordinated model of transition to ensure ongoing and appropriate care is critical. Enabling a smooth transfer begins with an understanding of the key differences between paediatric and adult NAFLD as well as the psychosocial factors that affect older adolescents. This Review summarizes the literature on paediatric NAFLD from the past two decades with a focus on the differences in epidemiology, pathology, pathophysiology and treatment that are relevant to clinicians who transition paediatric patients to adult care. An integrated model, which employs a team of adult and paediatric providers who can address the psychosocial, cognitive and logistical challenges of transition, provides the best opportunity for a seamless and coordinated transfer to adult care.

Chronic Exposure to TNFα Impairs Secretion of Glucagon-Like Peptide-1

Obesity is associated with systemic inflammation and elevated levels of TNFα, leading to impaired glucose tolerance. In humans, obesity is also associated with reduced nutrient-stimulated secretion of the intestinal incretin hormone, glucagon-like peptide-1 (GLP-1). We hypothesized that TNFα plays a direct role in the impairment of GLP-1 secretion from the enteroendocrine L-cell and that blocking TNFα can restore both GLP-1 secretion and glucose homeostasis. Expression of the TNFα receptor subytpe-1 was detected in the human NCI-H716 and murine GLUTag L-cell models and in mouse ileal sections. Although TNFα acutely increased GLP-1 release from NCI-H716 cells (P < .05-.001), preincubation with TNFα for 24 hours reduced proglucagon mRNA (P < .05) and GLP-1 cellular (P < .05) levels without affecting cell viability. Furthermore, both NCI-H716 and GLUTag cells pretreated with TNFα for 24 hours no longer responded to known GLP-1 secretagogues, an effect that was reversed by coincubation with the Nuclear Factor Kappa B inhibitor, 5-aminosalicylic acid, in the NCI-H716 cells. Mice given a high-fat diet (HFD) for 12 weeks developed impaired glucose tolerance, hyperinsulinemia, and increased TNFα mRNA expression in fat and ileal tissue. Hyperglycemia and hyperinsulinemia were reduced in HFD mice treated with the anti-TNFα biological, etanercept, for 2 weeks. In primary intestinal cultures from these animals, HFD control mice had impaired GLP-1 secretion, and this was not observed in the HFD etanercept-derived cultures (P < .05). In conclusion, chronic exposure to TNFα directly impairs GLP-1 secretion at the level of the intestinal L-cell, an effect that is reversed by anti-TNFα therapy in association with improved glucose tolerance.

Obesity-Related Behaviors among Poor Adolescents and Young Adults: Is Social Position Associated with Risk Behaviors?

HighlightsDifferent measures of social position capture unique dimensions of relative rank among youth.Youth-specific measures of social position may be important in identifying the most at-risk for obesity.Lower social status youth are more likely to be at-risk for obesity-related behaviors compared to those with a higher rank. This cross-sectional study examines multiple dimensions of social position in relation to obesity-related behaviors in an adolescent and young adult population. In addition to using conventional measures of social position, including parental education and household expenditures, we explore the usefulness of three youth-specific measures of social position - community and society subjective social status and school dropout status. Data are taken from a 2004 house-to-house survey of urban households within the bottom 20th percentile of income distribution within seven states in Mexico. A total of 5,321 Mexican adolescents, aged 12-22 years, provided information on obesity-related behaviors (e.g., diet, physical activity, sedentary behavior) and indicators of subjective and objective social position. A parent in each household provided information on socioeconomic status of the parent and household. Ordinal logistic regressions are used to estimate the associations of parental, household and adolescent indicators of social position and obesity-related risk behaviors. Those adolescents with the highest odds of adopting obesity risk behaviors were the ones who perceived themselves as lower in social status in reference to their peer community and those who had dropped out of school. We found no significant associations between parental education or household expenditures and obesity-related risk behaviors. Immediate social factors in adolescents' lives may have a strong influence on their health-related behaviors. This study provides evidence for the usefulness of two particular measures, both of which are youth-specific. Adolescents and young adults who have dropped out of school and those with lower perceived relative social position within their community are more likely to be at-risk for obesity-related behaviors than those with higher relative social position. We conclude that youth-specific measures may be important in identifying the most at-risk among relatively homogeneous populations of youth.

Obesity in children: bariatric surgery

INTRODUCTION

The prevalence of childhood obesity in the UK and in many countries worldwide remains high. Behavioural interventions to modify lifestyle, such as diet and physical activity, usually form part of weight management strategies for obese children. Whether or not surgical interventions are effective and safe in treating childhood obesity is unclear.

METHODS AND OUTCOMES

We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of surgical interventions for the treatment of childhood obesity? We searched Medline, Embase, The Cochrane Library, and other important databases up to August 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS

At this update, after deduplication and removal of conference abstracts, 67 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 19 studies and the further review of 48 full publications. Of the 48 full articles evaluated, two systematic reviews were included at this update.

CONCLUSIONS

In this systematic overview, we categorised the efficacy for two comparisons based on information about the effectiveness and safety of bariatric surgery versus no intervention and different types of bariatric surgery versus each other.

Monitoring human growth and development: a continuum from the womb to the classroom

A comprehensive set of fully integrated anthropometric measures is needed to evaluate human growth from conception to infancy so that consistent judgments can be made about the appropriateness of fetal and infant growth. At present, there are 2 barriers to this strategy. First, descriptive reference charts, which are derived from local, unselected samples with inadequate methods and poor characterization of their putatively healthy populations, commonly are used rather than prescriptive standards. The use of prescriptive standards is justified by the extensive biologic, genetic, and epidemiologic evidence that skeletal growth is similar from conception to childhood across geographic populations, when health, nutrition, environmental, and health care needs are met. Second, clinicians currently screen fetuses, newborn infants, and infants at all levels of care with a wide range of charts and cutoff points, often with limited appreciation of the underlying population or quality of the study that generated the charts. Adding to the confusion, infants are evaluated after birth with a single prescriptive tool: the World Health Organization Child Growth Standards, which were derived from healthy, breastfed newborn infants, infants, and young children from populations that have been exposed to few growth-restricting factors. The International Fetal and Newborn Growth Consortium for the 21st Century Project addressed these issues by providing international standards for gestational age estimation, first-trimester fetal size, fetal growth, newborn size for gestational age, and postnatal growth of preterm infants, all of which complement the World Health Organization Child Growth Standards conceptually, methodologically, and analytically. Hence, growth and development can now, for the first time, be monitored globally across the vital first 1000 days and all the way to 5 years of age. It is clear that an integrative approach to monitoring growth and development from pregnancy to school age is desirable, scientifically supported, and likely to improve care, referral patterns, and reporting systems. Such integration can be achieved only through the use of international growth standards, especially in increasingly diverse, mixed ancestry populations. Resistance to new scientific developments has been hugely problematic in medicine; however, we are confident that the obstetric and neonatal communities will join their pediatric colleagues worldwide in the adoption of this integrative strategy.

Overweight and obesity in young adult women: A matter of health or appearance? The Tromsø study: Fit futures

With the increasing number of overweight and obese people, there is a growing public health concern and focus on body size and lifestyle issues, especially in the media. Young adult women comprise a vulnerable group regarding issues of weight balance and appearance. The aim of the study was to examine the experiences of young women on how this focus influences their attitudes concerning weight changes, appearance, and health. We conducted 12 interviews with young women from two different weight groups about the attention on overweight issues. The results from the in-depth interviews were scrutinized through content analyses. The main findings indicate that young women experience a considerable focus on overweight issues with a trend towards appearance rather than health. Overweight and obesity are sensitive topics, and participants expressed strong views on the cultural definitions of normal body size and appearance. The squeeze between cultural norms and young women's perceptions of their own body and health was described as a possible negative factor influencing well-being as well as motivation for lifestyle changes. A more relaxed focus on overweight issues and especially on appearance is necessary when addressing weight-balance issues and lifestyle changes in young adult women.

Overweight, obesity, physical activity and sugar-sweetened beverage consumption in adolescents of Pacific islands: results from the Global School-Based Student Health Survey and the Youth Risk Behavior Surveillance System

BACKGROUND

Overweight, obesity and their consequences are challenges to sustainable social and economic development in Pacific island countries and territories (PICTs). Complementing previous analyses for adults, the purpose of this paper is to synthesise available data on overweight, obesity and their risk factors in adolescents in the region. The resulting Pacific perspective for the younger generation will inform both the national and regional public health response to the crisis of noncommunicable diseases.

METHODS

We examined the prevalence of overweight, obesity, physical activity and carbonated sugar-sweetened beverage (SSB) consumption, by using published results of two cross-sectional surveys: the Global School-Based Student Health Survey (GSHS) and the Youth Risk Behavior Surveillance System (YRBSS). GSHS was conducted in ten PICTs between 2010 and 2013 and provided results for 13-15 year olds. YRBSS surveys, conducted repeatedly in five PICTs between 1999 and 2013, provided results for grade 9-12 students (approximately 14-18 years) and enabled examination of trends.

RESULTS

Obesity prevalence ranged from 0 % in female students in Vanuatu to 40 % in males in Niue (GSHS). Among grade 9-12 students (YRBSS), obesity was highest in American Samoa (40 % of males; 37 % of females). Approximately 60 % of students in the Cook Islands, Niue and Tonga (GSHS) and American Samoa (YRBSS), were overweight. In both surveys, less than half of students reported engaging in sixty minutes of physical activity on at least 5 days of the past week. Daily consumption of carbonated SSBs in the past month was reported by over 42 % of students in six PICTs (GSHS), and in the past week by more than 18 % of students in three PICTs (YRBSS). In PICTs conducting YRBSS, obesity prevalence remained high or increased within the period 1999-2013.

CONCLUSION

There is a need for urgent action on overweight, obesity and their risk factors in Pacific youth. The multiple social, economic and physical determinants of this public health crisis must be addressed. This requires all sectors within government and society in PICTs to implement and evaluate policies that will protect and promote the health of their populations across the life course.

Helpful or harmful? Prospective association between weight misperception and weight gain among overweight and obese adolescents and young adults

BACKGROUND/OBJECTIVE

Weight misperception is common among adolescents with obesity, but it is not known whether weight perception is related to future weight gain. The objective of the study was to examine the prospective association between accurate weight perception versus weight misperception and weight change among youth who are overweight or obese.

SUBJECTS/METHODS

Using a subsample of The National Longitudinal Study of Adolescent to Adult Health Wave II cohort, we used linear regression modeling (adjusted for age, baseline body mass index (BMI), parental education, household percent federal poverty level, depression, race and ethnicity) to examine the prospective association between weight misperception (that is, perceiving oneself to be under or normal weight) among 2738 overweight and obese youth and subsequent BMI change from Wave II (1996) to Wave IV (2008-2009). Mean age at baseline (Wave II) was 15.9 (0.1).

RESULTS

Fifty-seven percent of males and 80% of females accurately perceived themselves as overweight. In fully adjusted models, weight misperception was associated with less BMI gain among youth who were overweight and obese. Specifically, youth who perceived themselves to be at a healthy weight had lower BMI gains (males: β= -1.43, 95% confidence interval (CI)=(-2.26, -0.60), P=0.001; females: β= -1.35, 95% CI=(-2.59, -0.11), P=0.035) from Wave II to IV relative to those who accurately perceived themselves as overweight or obese.

CONCLUSIONS

Contrary to commonly held assumptions, weight misperception among a non-clinical sample of youth who were overweight or obese predicted lower future weight gain. Efficacy of efforts to correct weight misperception should be rigorously examined to assess for both intended and unintended consequences.

A youth-led social marketing intervention to encourage healthy lifestyles, the EYTO (European Youth Tackling Obesity) project: a cluster randomised controlled0 trial in Catalonia, Spain

Background

The encouragement of healthy lifestyles for obesity prevention in young people is a public health priority. The European Youth Tackling Obesity (EYTO) project is a multicentric intervention project with participation from the United Kingdom, Portugal, the Czech Republic and Spain. The general aim of the EYTO project is to improve lifestyles, including nutritional habits and physical activity practice, and to prevent obesity in socioeconomically disadvantaged and vulnerable adolescents. The EYTO project works through a peer-led social marketing intervention that is designed and implemented by the adolescents of each participating country. Each country involved in the project acts independently. This paper describes the “Som la Pera” intervention Spanish study that is part of the EYTO project.

Methods/Design

In Spain, the research team performed a cluster randomised controlled intervention over 2 academic years (2013–2015) in which 2 high-schools were designated as the control group and 2 high-schools were designated as the intervention group, with a minimum of 121 schoolchildren per group.

From the intervention group, 5 adolescents with leadership characteristics, called “Adolescent Challenge Creators” (ACCs), were recruited. These 5 ACCs received an initial 4 h training session about social marketing principles and healthy lifestyle theory, followed by 24 sessions (1.30 h/session) divided in two academic years to design and implement activities presented as challenges to encourage healthy lifestyles among their peers, the approximately 180–200 high-school students in the intervention group. During the design of the intervention, it was essential that the ACCs used the 8 social marketing criteria (customer orientation, behaviour, theory, insight, exchange, competition, segmentation and methods mix). The expected primary outcomes from the Spanish intervention will be as follows: increases in the consumption of fruits and vegetables and physical activity practice along with reductions in TV/computer/game console use. The secondary outcomes will be as follows: increased breakfast consumption, engagement with local recreation and reduced obesity prevalence. The outcomes will be measured by the Health Behaviour in School-aged Children Study (HBSC) survey at baseline and at the end of the intervention.

In the control group, no intervention was implemented, but the outcome measurements were collected in parallel with the intervention group.

Discussion

This study described a new methodology to improve lifestyles and to address adolescent obesity.

Trial registration

ClinicalTrials.gov: NCT02157402. Registered 03 June 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1920-1) contains supplementary material, which is available to authorized users.

Strengthening of accountability systems to create healthy food environments and reduce global obesity

To achieve WHO's target to halt the rise in obesity and diabetes, dramatic actions are needed to improve the healthiness of food environments. Substantial debate surrounds who is responsible for delivering effective actions and what, specifically, these actions should entail. Arguments are often reduced to a debate between individual and collective responsibilities, and between hard regulatory or fiscal interventions and soft voluntary, education-based approaches. Genuine progress lies beyond the impasse of these entrenched dichotomies. We argue for a strengthening of accountability systems across all actors to substantially improve performance on obesity reduction. In view of the industry opposition and government reluctance to regulate for healthier food environments, quasiregulatory approaches might achieve progress. A four step accountability framework (take the account, share the account, hold to account, and respond to the account) is proposed. The framework identifies multiple levers for change, including quasiregulatory and other approaches that involve government-specified and government-monitored progress of private sector performance, government procurement mechanisms, improved transparency, monitoring of actions, and management of conflicts of interest. Strengthened accountability systems would support government leadership and stewardship, constrain the influence of private sector actors with major conflicts of interest on public policy development, and reinforce the engagement of civil society in creating demand for healthy food environments and in monitoring progress towards obesity action objectives.

Smart food policies for obesity prevention

Prevention of obesity requires policies that work. In this Series paper, we propose a new way to understand how food policies could be made to work more effectively for obesity prevention. Our approach draws on evidence from a range of disciplines (psychology, economics, and public health nutrition) to develop a theory of change to understand how food policies work. We focus on one of the key determinants of obesity: diet. The evidence we review suggests that the interaction between human food preferences and the environment in which those preferences are learned, expressed, and reassessed has a central role. We identify four mechanisms through which food policies can affect diet: providing an enabling environment for learning of healthy preferences, overcoming barriers to the expression of healthy preferences, encouraging people to reassess existing unhealthy preferences at the point-of-purchase, and stimulating a food-systems response. We explore how actions in three specific policy areas (school settings, economic instruments, and nutrition labelling) work through these mechanisms, and draw implications for more effective policy design. We find that effective food-policy actions are those that lead to positive changes to food, social, and information environments and the systems that underpin them. Effective food-policy actions are tailored to the preference, behavioural, socioeconomic, and demographic characteristics of the people they seek to support, are designed to work through the mechanisms through which they have greatest effect, and are implemented as part of a combination of mutually reinforcing actions. Moving forward, priorities should include comprehensive policy actions that create an enabling environment for infants and children to learn healthy food preferences and targeted actions that enable disadvantaged populations to overcome barriers to meeting healthy preferences. Policy assessments should be carefully designed on the basis of a theory of change, using indicators of progress along the various pathways towards the long-term goal of reducing obesity rates.

Patchy progress on obesity prevention: emerging examples, entrenched barriers, and new thinking

Despite isolated areas of improvement, no country to date has reversed its obesity epidemic. Governments, together with a broad range of stakeholders, need to act urgently to decrease the prevalence of obesity. In this Series paper, we review several regulatory and non-regulatory actions taken around the world to address obesity and discuss some of the reasons for the scarce and fitful progress. Additionally, we preview the papers in this Lancet Series, which each identify high-priority actions on key obesity issues and challenge some of the entrenched dichotomies that dominate the thinking about obesity and its solutions. Although obesity is acknowledged as a complex issue, many debates about its causes and solutions are centred around overly simple dichotomies that present seemingly competing perspectives. Examples of such dichotomies explored in this Series include personal versus collective responsibilities for actions, supply versus demand-type explanations for consumption of unhealthy food, government regulation versus industry self-regulation, top-down versus bottom-up drivers for change, treatment versus prevention priorities, and a focus on undernutrition versus overnutrition. We also explore the dichotomy of individual versus environmental drivers of obesity and conclude that people bear some personal responsibility for their health, but environmental factors can readily support or undermine the ability of people to act in their own self-interest. We propose a reframing of obesity that emphasises the reciprocal nature of the interaction between the environment and the individual. Today's food environments exploit people's biological, psychological, social, and economic vulnerabilities, making it easier for them to eat unhealthy foods. This reinforces preferences and demands for foods of poor nutritional quality, furthering the unhealthy food environments. Regulatory actions from governments and increased efforts from industry and civil society will be necessary to break these vicious cycles.

Obesity and Altered Sleep: A Pathway to Metabolic Derangements in Children?

Obstructive sleep apnea (OSA) is a frequent disorder in children and is primarily associated with adenotonsillar hypertrophy. The prominent increases in childhood overweight and obesity rates in the world even among youngest of children have translated into parallel increases in the prevalence of OSA, and such trends are undoubtedly associated with deleterious global health outcomes and life expectancy. Even an obesity phenotype in childhood OSA, more close to the adult type, has been recently proposed. Reciprocal interactions between sleep in general, OSA, obesity, and disruptions of metabolic homeostasis have emerged in recent years. These associations have suggested the a priori involvement of complex sets of metabolic and inflammatory pathways, all of which may underlie an increased risk for increased orexigenic behaviors and dysfunctional satiety, hyperlipidemia, and insulin resistance that ultimately favor the emergence of metabolic syndrome. Here, we review some of the critical evidence supporting the proposed associations between sleep disruption and the metabolism-obesity complex. In addition, we describe the more recent evidence linking the potential interactive roles of OSA and obesity on metabolic phenotype.

Control of Body Weight by Eating Behavior in Children

Diet, exercise, and pharmacological interventions have limited effects in counteracting the worldwide increase in pediatric body weight. Moreover, the promise that individualized drug design will work to induce weight loss appears to be exaggerated. We suggest that the reason for this limited success is that the cause of obesity has been misunderstood. Body weight is mainly under external control; our brain permits us to eat under most circumstances, and unless the financial or physical cost of food is high, eating and body weight increase by default. When energy-rich, inexpensive foods are continually available, people need external support to maintain a healthy body weight. Weight loss can thereby be achieved by continuous feedback on how much and how fast to eat on a computer screen.

Childhood Obesity Is a Chronic Disease Demanding Specific Health Care--a Position Statement from the Childhood Obesity Task Force (COTF) of the European Association for the Study of Obesity (EASO)

Childhood obesity is one of the greatest health challenges of the 21st century. The EASO COTF is convinced that classifying obesity as a chronic disease in children and adolescents is a crucial step for increasing individual and societal awareness, and for improving early diagnosis and intervention. Such a classification will enhance the development of novel preventive and treatment approaches, health care policies and systems, and the education of healthcare workers. The management of obesity prior to the appearance of co-morbidities may prevent their escalation into significant medical and psychosocial problems, and reduce their economic and societal impact. Childhood is a unique window of opportunity to influence lifetime effects on health, quality of life, prevention of non-communicable chronic diseases and disabilities. The Convention on the Rights of the Child by UNICEF states that parties shall strive to ensure that no child is deprived of his or her right of access to health care services. The EASO COTF is aiming to address these issues via educational activities for health care workers, identification of research agendas, and the promotion of collaborations among clinicians, researchers, health institutions, organizations and states across Europe.