Exploring the association between internalized weight bias and mental health among Canadian adolescents

BACKGROUND

Internalized weight bias (IWB) has been identified as a correlate of higher depressive and anxiety symptoms in adolescents with higher weights. However, there has been limited investigation into how IWB relates to positive mental health and whether these associations differ across genders.

OBJECTIVES

To examine the associations between IWB and mental health (depression, anxiety, flourishing) in adolescents with higher weights, and to test the potential moderating role of gender.

METHODS

Canadian adolescents with higher weights (N = 7538, 60% boys, 36% girls, 4% gender diverse, ages 12-19) from the COMPASS study completed a survey during the 2021-2022 school year. Data were analysed using generalized linear models.

RESULTS

Highest IWB and poorest mental health were noted within gender diverse adolescents, followed by girls then boys. Gender moderated the relationship between higher IWB and higher depression, higher anxiety and lower flourishing, with the strongest relationships noted among girls.

CONCLUSION

IWB interventions should be tailored to gender subgroups that may be particularly vulnerable to maladaptive mental health outcomes associated with IWB. System-level changes that mitigate perpetuation of weight bias and discrimination which lead to IWB are also essential, particularly for girls.

Weighty words: exploring terminology about weight among samples of physicians, obesity specialists, and the general public

BACKGROUND

The words used to refer to weight and individuals with large bodies can be used to reinforce weight stigma. Given that most previous research has examined preferred terminology within homogenous groups, this research sought to examine terminology preferences across populations.

METHODS

This paper reports on data gathered with the general public, family physicians, and obesity researchers/practitioners. Participants were asked about the words they commonly: (1) used to refer to people with large bodies (general public); (2) heard in their professional contexts (physicians and obesity specialists); and (3) perceived to be the most socially or professionally acceptable (all samples).

RESULTS

Similarities and differences were evident between samples, especially related to weight-related clinical terms, the word fat, and behavioral stereotypes.

CONCLUSION

The results provide some clarity into the differences between populations and highlight the need to incorporate use of strategies that may move beyond person-first language to humanize research and clinical practice with people with large bodies.

Assessment of electronic patient education materials for adolescent bariatric surgery candidates: An environment scan

Objective

Adolescents who opt for metabolic and bariatric surgery (MBS) will use the internet to learn about the procedure. The objective of this study is to assess the suitability of electronic patient education materials (ePEM) of North American centers that perform adolescent bariatric surgery.

Methods

Canadian and American bariatric centers that perform adolescent MBS were identified from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and Google web-based searches. Suitability of ePEM for the adolescent readership was evaluated using the Suitability Assessment of Materials (SAM).

Results

Sixty-five centers were evaluated from June to July 2020 with 41% citing adolescent specific material. Six percent of the ePEM were evaluated as 'not suitable', 69% were evaluated as 'adequate', and 25% were evaluated as 'superior'.

Conclusion

Adequate ePEM scoring was obtained, but centers had little resources tailored to adolescent patients. Further research is needed to evaluate all the resources provided to adolescents (i.e., resources provided by the health team) to ensure the tools are appropriate for the adolescent readership.

Innovation

This environmental scan provided insights to ePEM available for adolescents considering MBS.

Compensatory health motivations and behaviors scale: Development, evaluation, psychometric properties and a preliminary validation

The "Compensatory Health Beliefs" scale assesses the degree to which one believes that unhealthy behaviours can be compensated through healthier ones. However, no validated scale to assess compensatory weight-related behaviors exists. The study's objective was to develop (Study 1) and validate (Study 2) a questionnaire measuring compensatory health motivations and behaviors (CHMB) and to assess their associations with body mass index (BMI) and psychological weight-related measures. An initial 34-item measure was constructed based on a target sample's (Study 1, n = 158) suggestions and refined based on expert feedback. The measure was then tested in a representative Canadian adult sample (N = 1400, 48.7% male). The sample was stratified by sex and age and then randomly split into two (N = 701 for exploratory factor analysis; N = 699 for confirmatory factor analysis (CFA) cross-validation). Fit indices, standardized Cronbach's alphas and the associations between the CHMB model with cognitive restraint, weight concerns, and BMI were assessed in multiple linear regression models controlling for age and sex. The final CHMB model (n = 17 items) consisted of four subscales: (1) motivation, (2) use on special occasions, (3) general use, (4) compensatory health beliefs. Fit indices (Goodness of Fit Index = 0.922) and Cronbach's alphas were good (α = 0.88). In multiple linear regression models, all CHMB subscales were associated with greater cognitive restraint in eating. Compensatory behavior use on special occasions was associated with greater weight concern (B = 0.12, p < .0001), while general compensatory behavior use was associated with lower weight concern (B = -0.07, p < .05). None of the subscales were associated with BMI. The validated CHMB scale allows for the assessment of compensatory health motivations and behaviors in a Canadian population. Research on whether this scale can predict weight changes and general health is needed.

Overlooked Outcomes in Pediatric Obesity Management-Unintended Consequences

This Viewpoint describes unintended consequences of pediatric obesity treatment plans and the need for evidence balancing potential benefits vs harms of these plans.

Weight bias internalization and beliefs about the causes of obesity among the Canadian public

BACKGROUND

Explicit weight bias is known as negative attitudes and beliefs toward individuals due to their weight status and can be perpetuated through misconceptions about the causes of obesity. Individuals may also experience weight bias internalization (WBI) when they internalize negative weight-related attitudes and self-stigmatize. There is a paucity of research on the beliefs about the causes of obesity and the prevalence of WBI among public Canadian samples. The aim of this study was to describe these attitudes and beliefs about obesity among a large Canadian sample across the weight spectrum.

METHODS

A Canadian sample of adults (N = 942; 51% Women; mean age group = 45-54 years; mean body mass index [BMI] = 27.3 ± 6.7 kg/m2) completed an online questionnaire. Participants completed the Modified Weight Bias Internalization Scale, the Anti-Fat Attitudes Questionnaire, and the Causes of Obesity Questionnaire.

RESULTS

Mean WBI score within the entire sample was 3.38 ​​ ± 1.58, and females had higher mean scores as compared to males (p < 0.001). Mean scores were also higher among individuals with a BMI of > 30 kg/m2 (4.16 ± 1.52), as compared to individuals with a BMI of 25-30 kg/m2 (3.40 ± 1.50), and those with a BMI of 20-25 kg/m2 or below 18.5 kg/m2 (2.81 ± 1.44) (p < 0.001 for all). Forty four percent of Canadians believed behavioural causes are very or extremely important in causing obesity, 38% for environmental causes, 28% for physiological and 27% for psychosocial causes. Stronger beliefs in behavioural causes were associated with higher levels of explicit weight bias. No BMI differences were reported on the four different subscales of the Causes of Obesity Questionnaire.

CONCLUSIONS

Weight bias internalization is prevalent among Canadians across all body weight statuses, and the public endorses behavioural causes of obesity, namely physical inactivity and overeating, more than its other causes. Findings warrant the reinforcement of efforts aimed at mitigating weight bias by educating the public about the complexity of obesity and by highlighting weight bias as a systemic issue that affects all Canadians living in diverse body weight statuses.

A qualitative exploration on the needs of health care providers working with adolescents who are undergoing bariatric surgery

Background

With increasing prevalence of severe obesity in youth, more adolescents are becoming candidates for bariatric surgery. In Canada, bariatric surgery in adolescents is in its infancy, and long-term health outcomes are not well known. It is unknown what health care providers (HCPs) are using to prepare and guide their adolescent patients for bariatric surgery. The needs of HCPs should be explored with the aim to improve patient outcomes. Therefore, the purpose of this study was to investigate the resource needs of HCPs working with adolescents living with severe obesity who are undergoing bariatric surgery.

Methods

This qualitative study consisted of a focus group with seven HCPs from an adolescent bariatric program using a semi-structured interview guide. The focus group discussion was audio-recorded, and the recording was transcribed verbatim. A thematic analysis was conducted.

Results

Four data-generated themes emerged highlighting the perceived needs and challenges faced by HCPs. These included (1) gaps in patient education materials on the subject of the bariatric surgery process, obesity as a chronic disease and mental health, (2) the need for designing resources that are teen-friendly, adaptable, and accessible, (3) the need for resources to facilitate decision-making and patient evaluation delivering more streamlined care and; (4) challenges to addressing resource needs due to limited clinical time and budgets.

Conclusion

This needs assessment study highlights the need for appropriate resources for patient education, as well as pre and post-operative preparation. The hope is that HCPs can improve quality of care delivered and positively impact surgical outcomes in their patients.

Predictors of support for anti-weight discrimination policies among Canadian adults

Introduction

Weight discrimination of individuals with overweight or obesity is associated with adverse mental and physical health. Weight discrimination is prevalent in many sectors such as within workplaces, where individuals with overweight and obesity are denied the same opportunities as individuals with lower weight status, regardless of performance or experience. The purpose of this study was to understand the Canadian public's support or opposition of anti-weight discrimination policies and predictors of support. It was hypothesized that Canadians will show support of anti-weight discrimination policies to some extent.

Methods

A secondary analysis was conducted on a previous cross-sectional sample of Canadian adults (N = 923, 50.76% women, 74.4% White) who responded to an online survey assessing weight bias and support of twelve anti-weight discrimination policies related to societal policies (e.g., implementing laws preventing weight discrimination) and employment-related policies (e.g., making it illegal to not hire someone due to their weight). Participants completed the Causes of Obesity Questionnaire (COB), the Anti-Fat Attitudes Questionnaire (AFA) and the Modified Weight Bias Internalization Scale (WBIS-M). Multiple logistic regressions were used to determine predictors of policy support.

Results

Support for policies ranged from 31.3% to 76.9%, with employment anti-discrimination policies obtaining greater support than societal policies. Identifying as White and a woman, being over the age of 45 and having a higher BMI were associated with an increased likelihood of supporting anti-weight discrimination policies. There were no differences between the level of support associated with attributing obesity to behavioral or non-behavioral causes. Explicit weight bias was associated with a reduced likelihood of supporting 8/12 policies. Weight Bias Internalization was associated with an increased likelihood of supporting all societal policies but none of the employment policies.

Conclusions

Support for anti-weight discrimination policies exists among Canadian adults, and explicit weight bias is associated with a lower likelihood of supporting these policies. These results highlight the need for education on the prevalence and perils of weight discrimination which may urge policy makers to consider weight bias as a form of discrimination that must be addressed. More research on potential implementation of anti-weight discrimination policies in Canada is warranted.

Exploring weight bias internalization in pregnancy

Background

Recent research has shown that pregnant individuals experience weight stigma throughout gestation, including negative comments and judgement associated with gestational weight gain (GWG). Weight bias internalization (WBI) is often a result of exposure to weight stigma and is detrimental to biopsychological health outcomes. The purpose of this study was to explore WBI in pregnancy and compare scores based on maternal weight-related factors including pre-pregnancy body mass index (BMI), obesity diagnosis and excessive GWG.

Methods

Pregnant individuals in Canada and USA completed a modified version of the Adult Weight Bias Internalization Scale. Self-reported pre-pregnancy height and weight were collected to calculate and classify pre-pregnancy BMI. Current weight was also reported to calculate GWG, which was then classified as excessive or not based on Institute of Medicine (2009) guidelines. Participants indicated if they were diagnosed with obesity by a healthcare provider. Inferential analyses were performed comparing WBI scores according to pre-pregnancy BMI, excessive GWG, and obesity diagnosis. Significance was accepted as p < 0.05 and effect sizes accompanied all analyses.

Result

336 pregnant individuals completed the survey, with an average WBI score of 3.9 ± 1.2. WBI was higher among those who had a pre-pregnancy BMI of obese than normal weight (p = 0.04, η² = 0.03), diagnosed with obesity than not diagnosed (p < 0.001, Cohen’s d = 1.3), and gained excessively versus not (p < 0.001, Cohen’s d = 1.2).

Conclusions

Pregnant individuals who have a higher BMI, obesity and gain excessively may experience WBI. Given that weight stigma frequently occurs in pregnancy, effective person-oriented strategies are needed to mitigate stigma and prevent and care for WBI.

Effects of the HEARTY exercise randomized controlled trial on eating behaviors in adolescents with obesity

Background

There are well-recognized benefits of behavioral interventions that include exercise for children and adolescents with obesity. However, such behavioral weight management programs may precipitate unintended consequences. It is unclear if different exercise modalities impact eating behaviors differently in youth with obesity.

Objectives

The purpose of this study was to examine the effects of aerobic, resistance, and combined aerobic and resistance exercise training on eating attitudes and behaviors (uncontrolled eating, restrained eating, emotional eating, external eating and food craving) among adolescents with overweight and obesity.

Methods

N = 304 (70% female) adolescents with overweight and obesity participated in the 6-month Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) randomized controlled trial. All participants were inactive post-pubertal adolescents (15.6 ± 1.4 years) with a mean BMI = 34.6 ± 4.5 kg/m². The Food Craving Inventory (food cravings), Dutch Eating Behavior Questionnaire (restrained eating, emotional eating, external eating), and the Three-Factor Eating Questionnaire (uncontrolled eating) were used to assess eating attitudes and behaviors.

Results

All exercise groups showed within-group decreases in external eating and food cravings. Participants randomized to the Combined training group and were more adherent showed the greatest improvements in eating behaviors and cravings.

Conclusions

A 6-month exercise intervention produced improvements in disordered eating behaviors and food cravings, but effects may be gender and modality-specific. Findings highlight the need to tailor exercise intervention to participant characteristics for the promotion of healthier eating and weight management outcomes in youth with obesity.

Clinical Trial Registration # and Date: ClinicalTrials.Gov NCT00195858, September 12, 2005.

The relationship between weight bias internalization and healthy and unhealthy weight control behaviours

PURPOSE

Weight bias internalization (WBI) is associated with disordered eating symptomology and motivation to control weight. The relationship between WBI and specific weight control behaviours and how these behaviours differ between men and women is not well understood. The objectives of this study are to determine (1) the relationship between WBI and weight control behaviours, (2) whether weight perception is independently associated with weight control behaviours, and (3) whether these relationships differ between men and women.

METHODS

Canadian adults (N = 161; 52.8% women; body mass index [BMI] = 26.5 ± 4.99 kg/m²) completed questionnaires pertaining to WBI, weight control behaviours (healthy, unhealthy, extreme) and weight perception (accurate, under-, or over-estimation compared with objectively measured BMI). The cross-sectional relationship between (1) WBI or (2) weight perception with the total number of healthy and unhealthy or extreme weight control behaviours, and likelihood of performing specific weight control behaviours were assessed with linear, and logistic regression models, respectively. All analyses were conducted adjusting for age, gender, and race. Subsequent analyses were stratified by sex.

RESULTS

WBI was associated with an increased likelihood of performing exercise for weight loss (OR 2.28, p < 0.05); increased likelihood of skipping meals in women (OR 2.57, p < 0.01), and consuming little amounts of food and food substitutes in men (OR 2.28, p < 0.01 and OR 2.17, p < 0.05, respectively). Weight perception was not associated with weight control behaviours.

CONCLUSIONS

WBI was associated with various weight control behaviours. This study highlights the importance of assessing WBI in clinical practice with patients seeking to manage their weight. Future longitudinal research should be conducted to further understand the behavioural and health effects from WBI.

LEVEL V

Cross-sectional descriptive study.

Associations of the BDNF Val66Met Polymorphism With Body Composition, Cardiometabolic Risk Factors, and Energy Intake in Youth With Obesity: Findings From the HEARTY Study

The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is functionally related to BDNF, and is associated with obesity and metabolic complications in adults, but limited research exists among adolescents. This study comparatively examined carriers and non-carriers of the BDNF Val66Met polymorphism on body composition, energy intake, and cardiometabolic profile among adolescents with obesity. The sample consisted of 187 adolescents with obesity; 99 were carriers of the homozygous Val (G/G) alleles and 88 were carriers of the Val/Met (G/A) or Met (A/A) alleles. Cardiometabolic profile and DNA were quantified from fasted blood samples. Body composition was assessed by magnetic resonance imaging (MRI). Compared to carriers of the homozygous Val (G/G) allele, carriers of the Val/Met (G/A) or Met/Met (A/A) variants exhibited significantly higher protein (p = 0.01) and fat (p = 0.05) intake, C-Reactive protein (p = 0.05), and a trend toward higher overall energy intake (p = 0.07), fat-free mass (p = 0.07), and lower HDL-C (p = 0.07) Results showed for the first time that among youth with obesity, carriers of the Val66Met BDNF Met-alleles exhibited significantly higher C-reactive protein and energy intake in the form of fat and protein compared to Val-allele carriers, thereby providing support for the possible role of BDNF in appetite, weight, and metabolic regulation during adolescence. Clinical Trial Registration: http://clinicaltrials.gov/, identifier NCT00195858.

Weight bias and support of public health policies

OBJECTIVES

Public health policies have been proposed to help address prevalent Canadian obesity rates. Along with the increase in obesity prevalence, explicit weight bias is also rampant in Western society. This paper aimed to assess the association between explicit weight bias attitudes and Canadian public support of these policy recommendations.

METHODS

Canadian adults (N = 903; 51% female; BMI = 27.3 ± 7.0 kg/m²) completed an online survey measuring explicit weight bias, using the three subscales of the Anti-Fat Attitudes Questionnaire: Willpower (belief in weight controllability), Fear of fat (fear of gaining weight), and Dislike (antipathy towards people with obesity). Whether these subscales were associated with policy support was assessed with logistic regression. Analyses were adjusted for age, race, gender, and income.

RESULTS

Public support of policy recommendations ranged from 53% to 90%. Explicit weight bias was primarily expressed through a fear of weight gain and the belief that weight gain was within the individual's control based on willpower. Although the Dislike subscale was associated with lower support for several policies that enable or guide individual choice in behaviour change, the Willpower and Fear of fat subscales were associated with greater support for similar policies.

CONCLUSION

This study contributes to evidence-informed public health action by describing public support of public health policies and demonstrating an association between explicit weight bias and public support. A higher total explicit weight bias score increased the odds of supporting primarily less intrusive policies. However, dislike of individuals with obesity was associated with decreased odds of supporting many policies.

Screen time is independently associated with serum brain-derived neurotrophic factor (BDNF) in youth with obesity

Low levels of brain derived-neurotrophic factor (BDNF) and excessive screen exposure are risk factors for neurocognitive deficits and obesity in youth, but the relationship between screen time and BDNF remains unknown. This study examined whether duration and/or type of sedentary screen time behaviour (TV viewing, video games, recreational computer use) are associated with serum BDNF levels in youth with obesity. The sample consisted of 250 inactive, postpubertal adolescents with obesity (172 females/78 males, aged 15.5 ± 1.4 years) at the baseline assessment of the Healthy Eating, Aerobic, Resistance Training in Youth Study. After controlling for self-reported age, sex, race, parental education, puberty stage, physical activity, and diet, higher total screen exposure was significantly associated with lower serum BDNF levels (β = -0.21, p = 0.002). TV viewing was the only type of screen behaviour that was associated with BDNF levels (β = -0.22, p = 0.001). Higher exposure to traditional forms of screen time was independently associated with lower serum BDNF levels, and this association appears to be driven primarily by TV viewing. Future intervention research is needed to determine whether limiting screen time is an effective way to increase BDNF and associated health benefits in a high-risk population of youth with obesity. Trial Registration: ClinicalTrials.Gov NCT00195858. Novelty: This study is the first to show that recreational screen time is inversely associated with serum BDNF levels. The inverse association between screen time and BDNF is driven primarily by TV viewing, indicating the type of screen might matter.

Predictors of Weight Bias in Exercise Science Students and Fitness Professionals: A Scoping Review

BACKGROUND

Although previous studies have reported weight bias among students and professionals in exercise science, physical education, kinesiology, and fitness instruction, predictors of weight bias in these professions have not been extensively reviewed.

AIM

The purpose of this scoping review was to explore the available literature on predictors of weight bias in exercise science students and fitness professionals to identify key concepts and research gaps.

METHODS

PubMed and ERIC were searched from January 1990 to May 2019. Eighteen studies were included in this review. A thematic analysis was conducted. Findings. Six main themes were drawn from these studies including beliefs in the personal controllability of weight; sex differences; enrollment in a health sciences-related program; psychosocial and personal factors; knowledge of obesity; lack of personal history, family, or friend with obesity. Our scoping review highlighted diverse predictors of weight bias among exercise science students and professionals that warrant further study and intervention.

The Association Between Weight-Based Teasing from Peers and Family in Childhood and Depressive Symptoms in Childhood and Adulthood: A Systematic Review

RECENT FINDINGS

Depressive symptoms may be a psychological correlate of weight-based teasing from peers and/or family. However, it is unclear whether the association of weight-based teasing with depressive symptoms differs by time (short term vs. long term), sex (males vs. females), or source (family vs. peers).

PURPOSE

The purpose of this systematic review was to (1) examine whether the frequency of weight-based teasing differs according to sex and source and; (2) examine whether the association of weight-based teasing with depressive symptoms varies according to time, sex, and source.

METHODS

On February 16, 2018, a combination of keywords within three concepts, (i) children and adults, (ii) weight-based teasing source, and (iii) mental health outcomes, were searched in four databases (PubMed, PsycINFO, Scopus, and Web of Science) for relevant articles. Cross-sectional and longitudinal original research articles were included, and studies were excluded if the relationship between weight-based teasing and depressive symptoms was not explicitly measured.

RESULTS

The search yielded 3572 articles, and nineteen studies were included in the final analysis. Experiences of weight-based teasing occurred significantly more among girls than boys. Weight-based teasing was significantly associated with depressive symptoms in both short and long term. Weight-based teasing exhibited a greater association with depressive symptoms in girls vs. boys and when it came from multiple sources than from either source alone. However, it remains uncertain whether one source of teasing is more common than the other, since only two studies found peers to be a more common source of weight-based teasing compared to family. Weight-based teasing from peers and family is associated with depressive symptoms, and girls are more psychologically vulnerable than boys. Interventions are required to reduce weight-based teasing and its harmful psychological effects.

Weight Bias in Educational Settings: a Systematic Review

PURPOSE

To conduct a systematic literature review of empirical peer-reviewed published studies on the prevalence of weight bias among students, pre-service, and in-service teachers and its impact on the educational experiences and health of students from kindergarten to postsecondary settings.

METHODS

Keywords were searched on three main concepts, (i) weight bias/stigma, (ii) obesity/overweight, and (iii) education, within eight databases. Our search yielded 8323 individual records, of which 45 studies satisfied our inclusion criteria.

RESULTS

Most studies were conducted in K-12 school settings (n = 41), were quantitative in design (n = 37), and used student samples (n = 18). Weight bias is prevalent in educational settings, among peers at school as well as pre-service and in-service teachers, and negatively impacts students' health and educational experiences.

CONCLUSION

These results highlighted the impact of weight bias in creating inequity for students with obesity as well as several underexamined areas, such as weight bias in postsecondary settings and attitudes among teachers and pre-service teachers. Innovative strategies to address weight bias in educational settings are needed.

Interindividual variability and individual responses to exercise training in adolescents with obesity

This study investigated the impact of exercise training on interindividual variability and response rates in body composition and cardiometabolic outcomes in adolescents with obesity. Postpubertal males and females (n = 143) were randomly assigned to 6 months of a diet-only control or aerobic, resistance, or combined exercise training. Body composition indices were percentages of body fat mass and lean body mass and waist circumference. Biomarkers of cardiometabolic health were systolic blood pressure and plasma fasting glucose, triglycerides, and high-density lipoprotein cholesterol. Interindividual variability was examined by comparing the standard deviation of individual responses (SD_IR) to a smallest robust change (SRC). The typical error of measurement was used to classify responses. SD_IR exceeded the SRC for percent body fat mass in all exercise groups (SRC = 1.04%; aerobic SD_IR = 1.50%; resistance SD_IR = 1.22%; combined SD_IR = 2.29%), percent lean body mass (SRC = 1.38%; SD_IR = 3.2%,), systolic blood pressure (SRC = 2.06 mm Hg; SD_IR = 4.92 mm Hg) in the resistance group, and waist circumference (SRC = 2.33 cm; SD_IR = 4.09 cm), and fasting glucose (SRC = 0.08 mmol/L; SD_IR = 0.28 mmol/L) in the combined group. However, half of the reported variables (11/21) did not have a positive SD_IR. Importantly, adverse response rates were significantly lower in all 3 exercise groups compared with control for body composition. Although exercise had a small influence on interindividual variability for indices of body composition, the rate of adverse responses did not increase for any outcome. Novelty Interindividual variability and individual responses to exercise training have not been investigated in adolescents with obesity. Six months of exercise training does not increase interindividual variability in adolescents with obesity. Exercise created a positive, uniform shift in responses.

Youth get a D+ grade in physical activity: How can we change public health messages to help reverse this trend?

The purpose of this paper is to critique how the promotion of physical activity (PA) is communicated and offer evidence-based alternative framings to encourage PA in youth. We argue that PA promotion messaging should not be tied to outcomes that focus on changing physical appearance, preventing or treating diseases, or sport performance or competition. From a public health perspective, we suggest that PA should instead focus on campaigns, policies, and programs that tie PA to enjoyment, wellbeing, and play.

Examining Weight Bias among Practicing Canadian Family Physicians

OBJECTIVES

The aim of this study was to examine the attitudes of practicing Canadian family physicians about individuals with obesity, their healthcare treatment, and perceptions of obesity treatment in the public healthcare system.

METHOD

A national sample of Canadian practicing family physicians (n = 400) completed the survey. Participants completed measures of explicit weight bias, attitudes towards treating patients with obesity, and perceptions that people with obesity increase demand on the public healthcare system.

RESULTS

Responses consistent with weight bias were not observed overall but were demonstrated in a sizeable minority of respondents. Many physicians also reported feeling frustrated with patients with obesity and agreed that people with obesity increase demand on the public healthcare system. Male physicians had more negative attitudes than females. More negative attitudes towards treating patients with obesity were associated with greater perceptions of them as a public health demand.

CONCLUSION

Results suggest that negative attitudes towards patients with obesity exist among some family physicians in Canada. It remains to be determined if physicians develop weight bias partly because they blame individuals for their obesity and its increased demand on the Canadian public healthcare system. More research is needed to better understand causes and consequences of weight bias among health professionals and make efforts towards its reduction in healthcare.

Effects of aerobic training, resistance training, or both on brain-derived neurotrophic factor in adolescents with obesity: The hearty randomized controlled trial

Brain derived neurotrophic factor (BDNF) is a protein that plays a critical role in modulating cognition in animals and humans. Aerobic exercise often increases BDNF in adults, but effects of this exercise modality and others among adolescents remain uncertain. This study examined the effects of aerobic training, resistance training, and combined training on resting serum BDNF levels in adolescents with overweight and obesity. After a 4-week pre-randomization treatment, 304 post-pubertal, adolescents with overweight or obesity (70% females) aged 14-18 years were randomized to one of four groups for 22 weeks: aerobic training (N = 75), resistance training (N = 78), combined aerobic and resistance training (N = 75), or non-exercising control (N = 76). All participants received dietary counseling targeting a daily energy deficit of 250 kcal. The exercise prescription was 4 times per week, progressing to 45 min/session for the aerobic and resistance groups and 90 min/session for the combined group. Resting serum BDNF levels were measured at baseline and 6-months. Results showed that in both intention-to-treat (ITT) and per protocol (≥70% adherence to prescribed sessions) analyses, there were no significant within- or between-group changes in BDNF. Findings indicate that aerobic training, resistance training or their combination did change serum BDNF levels in adolescents with overweight and obesity.

TRIAL REGISTRATION

ClinicalTrials.Gov NCT00195858 http://clinicaltrials.gov/show/NCT00195858, September 12, 2005 (Funded by the Canadian Institutes of Health Research).

Fitspiration and thinspiration: a comparison across three social networking sites

BACKGROUND

Fitspiration, or images and text promoting health and fitness, and thinspiration, or images and text promoting thinness, have both received criticism for their negative effects on body image and dieting behaviors. In this study, we critically examined and compared the content of fitspiration and thinspiration on three social networking sites (SNS).

METHODS

Fitspiration and thinspiration posts (N = 360) from three photo-sharing SNS (Instagram, Tumblr, and Twitter) were collected quasi-randomly on four days over two weeks. Image and associated text content were coded for variables related to weight and shape, muscularity, thin ideal, and eating. Chi-square and Fisher's exact tests compared content of fitspiration and thinspiration posts overall and among the three SNS.

RESULTS

Thinspiration images portrayed body parts more frequently than fitspiration (69.8% vs. 30.2%). Similarly, posts highlighting bony body features and references to mental illness appeared only in thinspiration. No differences were found between fitspiration and thinspiration posts with regard to sexual suggestiveness, appearance comparison, and messages encouraging restrictive eating. Fitspiration and thinspiration posts included similar images across the three SNS-focusing on appearance, sexually suggestive images, and restrictive eating-with three exceptions. Fitspiration posts exhibiting body positivity were found only on Tumblr. In thinspiration posts, references to mental illness were more frequent on Tumblr and Instagram than on Twitter, and bone emphasis was coded more frequently on Twitter than on Instagram.

CONCLUSIONS

Although fitspiration posts were less extreme than thinspiration posts on the whole, notable similarities in their content support that fitspiration endorses problematic attitudes towards fitness, body image, and restrictive eating in pursuit of a fit-and-thin body ideal.

Canadian Senate Report on Obesity: Focusing on Individual Behaviours versus Social Determinants of Health May Promote Weight Stigma

Very little attention has been given to unintended consequences of government reporting on obesity. This paper argues that the 2016 Senate report, "Obesity in Canada: A Whole-Of-Society Approach," exemplifies the systemic public health issue of weight stigma. The purpose of this viewpoint is to critique the approach taken in the Report, by illustrating that it (1) takes a weight-centric approach to health, (2) does not acknowledge important limitations of the definition and measurement of obesity, (3) reifies obesity as a categorical phenomenon that must be prevented, and (4) uses aggressive framing and disrespectful terminology. The Report perpetuates a focus on the individual, thereby failing to recognize the role that governments can play in reducing weight stigma and addressing social determinants of health. If steps are taken to avoid propagating weight stigma, future reports could more constructively address health promotion, equity, and social determinants of health in their policies.

Addressing weight bias and discrimination: moving beyond raising awareness to creating change

Weight discrimination is the unjust treatment of individuals because of their weight. There have been very few interventions to address weight discrimination, due in part to the lack of consensus on key messages and strategies. The objective of the third Canadian Weight Bias Summit was to review current evidence and move towards consensus on key weight bias and obesity discrimination reduction messages and strategies. Using a modified brokered dialogue approach, participants, including researchers, health professionals, policy makers and people living with obesity, reviewed the evidence and moved towards consensus on key messages and strategies for future interventions. Participants agreed to these key messages: (1) Weight bias and obesity discrimination should not be tolerated in education, health care and public policy sectors; (2) obesity should be recognized and treated as a chronic disease in health care and policy sectors; and (3) in the education sector, weight and health need to be decoupled. Consensus on future strategies included (1) creating resources to support policy makers, (2) using personal narratives from people living with obesity to engage audiences and communicate anti-discrimination messages and (3) developing a better clinical definition for obesity. Messages and strategies should be implemented and evaluated using consistent theoretical frameworks and methodologies.

Depressive symptoms, perceived stress, self-efficacy, and outcome expectations: Predict fitness among adolescents with obesity

The objective of the present study was to test if outcome expectancy mediated the relationship between fitness and self-efficacy, perceived stress, and depressive symptoms.Adolescents with obesity (n = 228) completed measures of perceived stress and depressive symptoms at baseline, self-efficacy and outcome expectancy at baseline and 3 months, and fitness at baseline and 6 months. Structural equation modeling was used to analyze the data. Results showed that self-efficacy was positively associated with fitness via outcome expectancies. For females, fewer depressive symptoms were linked to fitness via self-efficacy and outcome expectancies. Exercise interventions that enhance exercise self-efficacy, outcome expectancy, and reduce depressive symptoms may increase fitness.

The use of magnetic resonance imaging to characterize abnormal body composition phenotypes in youth with Prader-Willi syndrome

INTRODUCTION

Magnetic resonance imaging (MRI) provides detailed assessment of body composition compartments. No studies have employed state-of-the-art MRI methods to accurately examine abdominal adipose tissue (AT) and skeletal muscle in youth with Prader-Willi syndrome (PWS). Therefore, this study aimed to describe AT distribution and skeletal muscle in the abdominal region of youth with PWS using MRI.

METHODS

Anthropometric measures and whole-abdominal T1-weighted MRI were performed in sixteen (5 males and 11 females) youth diagnosed with PWS, and seventeen (10 males and 7 females) youth who did not have PWS (controls). Volume of subcutaneous, visceral, intermuscular, and total AT, and skeletal muscle in the abdominal region were quantified using a semiautomatic procedure. Results were summarized using median and interquartile range (IQR, 25th-75th), and ANCOVA test was used (with age and sex as covariates) to examine differences in body composition compartments between PWS and control group.

RESULTS

PWS group had similar age (10.5, 6.6-13.9 vs. 12.8, 10.0-14.4years; P=0.14) and BMI z-score (0.5, 0.2-1.3 vs. 0.2, -0.3 to 1.0; P=0.33) when compared with controls. Significant differences were observed in absolute volumes of total AT (PWS: 4.1, 2.0-6.6L; control: 2.9, 2.0-4.5L; P=0.01), subcutaneous AT (PWS: 2.8, 1.4-4.8L; control: 1.8, 1.1-3.2L; P=0.01), and intermuscular AT (PWS: 0.3, 0.1-0.4L; control: 0.3, 0.2-0.3L; P<0.005). Visceral AT/subcutaneous AT was lower in PWS (0.4, 0.3-0.5) compared to controls (0.5, 0.4-0.6), P=0.01. In addition, skeletal muscle volume was lower in PWS (1.5, 1.0-2.6L) compared to controls (3.1, 1.6-3.9L), P=0.03. Ratios of abdominal AT compartments to skeletal muscle were all higher in PWS compared to controls (all P<0.005).

CONCLUSIONS

PWS youth have greater abdominal adiposity, particularly subcutaneous AT and intermuscular AT, and lower volume of skeletal muscle compared to controls. The decreased ratio of visceral AT/subcutaneous AT in youth with PWS suggests an improved metabolic profile for the level of adiposity present; however, elevated ratios of AT to skeletal muscle suggest a sarcopenic obesity-like phenotype, which could lead to worse health outcomes.

Effects of aerobic or resistance training or both on health-related quality of life in youth with obesity: the HEARTY Trial

This study examined the effects of aerobic and resistance training, and their combination on health-related quality of life (HRQoL) in adolescents with overweight or obesity. After a 4-week run-in period, 304 (91 males, 213 females) post-pubertal adolescents aged 14-18 years, were randomized to 4 groups for 22 weeks of: aerobic training (n = 75), resistance training (n = 78), combined aerobic and resistance training (n = 75), or nonexercising control (n = 76). All participants received dietary counseling with a daily energy deficit of 250 kcal. Indicators of HRQoL such as overall HRQoL, and physical and psychosocial (an aggregate of emotional, social, and school functioning) HRQoL at baseline and 6 months postintervention were measured by the Pediatric Quality of Life questionnaire. The trial began in March 2005 and was completed in June 2011. In the intention-to-treat analyses, all groups showed significant improvements at 6 months on all HRQoL indicators. The aerobic group showed greater improvements than controls on physical HRQoL (mean differences of 5.5; 95% CI; 1.4-9.6, p = 0.009). In participants with ≥70% adherence, combined training produced greater improvements than control on overall HRQoL (mean differences of 4.8, 95% CI; 0.7-9.0, p = 0.02), physical HRQoL (mean differences of 5.8; 95% CI: 0.6-10.7; p = 0.03), social HRQoL (mean differences of 7.6; 95% CI: 1.0-14.2; p = 0.02), and school-based HRQoL (mean differences of 7.6; 95% CI: 1.0-14.2; p = 0.02). These findings highlight the potential importance of including resistance exercise into traditional aerobic exercise programs to maximize HRQoL in adolescents with obesity.

Weight bias: a call to action

Weight-related issues (including excess weight, disordered eating and body concerns) are often considered as comprising distinct domains of 'obesity' and 'eating disorders'. In this commentary we argue that the concept of weight bias is an important variable when considering wellbeing across the spectrum of weight-related issues. We make the following six points in support of this argument: i) weight bias is common and has adverse health consequences, ii) shaming individuals for their body weight does not motivate positive behaviour change, iii) internalized weight bias is particularly problematic, iv) public health interventions, if not carefully thought out, can perpetuate weight bias, v) weight bias is a manifestation of social inequity, and vi) action on weight bias requires an upstream, population-level approach. To achieve sustainable reductions in weight bias at a population level, substantive modifications and collaborative efforts in multiple settings must be initiated. We provide several examples of population-level interventions to reduce weight bias.

Does exercise training affect resting metabolic rate in adolescents with obesity?

We evaluated the hypothesis that resistance exercise training performed alone or in combination with aerobic exercise training would increase resting metabolic rate (RMR) relative to aerobic-only and nonexercising control groups. Postpubertal adolescents (N = 304) aged 14-18 years with obesity (body mass index (BMI) ≥ 95th percentile) or overweight (BMI ≥ 85th percentile + additional diabetes risk factor(s)) were randomized to 4 groups for 22 weeks: Aerobic exercise training, Resistance exercise training, Combined aerobic and resistance exercise training, or Control. All participants received dietary counselling targeting a daily energy deficit of 250 kcal. RMR was measured by indirect calorimetry and body composition by magnetic resonance imaging. There was no significant change in RMR in any group, in spite of significant within-group increases in fat-free mass in the Aerobic, Resistance, and Combined exercise training groups. RMR at baseline and 6 months were Aerobic: 1972 ± 38 and 1990 ± 41; Resistance: 2024 ± 37 and 1992 ± 41; Combined: 2023 ± 38 and 1995 ± 38; Control: 2075 ± 38 and 2073 ± 39 kcal/day (p > 0.05). There were no between-group differences in RMR after adjustment for total body weight or fat-free mass between groups over time. Per-protocol analyses including only participants with ≥70% adherence, and analyses stratified by sex, also showed no within- or between-group differences in RMR. In conclusion, despite an increase in fat-free mass in all exercise groups, 6 months of aerobic, resistance, or combined training with modest dietary restriction did not increase RMR compared with diet only in adolescents with obesity.

The mediating role of energy intake on the relationship between screen time behaviour and body mass index in adolescents with obesity: The HEARTY study

Adolescents spend up to 6-8 h/day in sedentary screen behaviour and screen time is an independent risk factor for obesity. However, the mechanisms by which screen time confers obesity risk remain unclear. Via community level recruitment this study examined whether the relationship between screen time behaviours and body mass index (BMI: kg/m²) was mediated by total energy intake or macronutrient consumption. In a cross-sectional study of post-pubertal adolescents (N = 283: 86M, 197F) with overweight or obesity at baseline of an intervention for weight control, we examined self-reported total energy intake (mean Calories from 3 day food diary), macronutrient intake (grams/day of carbohydrate, fat, protein) and total screen time (aggregate of hours/day watching TV, playing seated video games, and recreational computer use). BMI was objectively measured and converted to standardized scores (z-BMI). Simple and multiple mediation analyses were conducted using the bootstrapping approach described by Preacher and Hayes. Covariates included age, sex, ethnicity, parental education, Tanner stage, and self-reported physical activity. The relationship between screen time and z-BMI was significantly mediated by energy intake. Higher levels of carbohydrate intake, but not fat or protein intake, significantly mediated the relationship between screen time and z-BMI (95% bias-corrected and accelerated confidence interval [0.0004, 0.0074]). Higher carbohydrate intake mediated the relationship between TV viewing and z-BMI, and video gaming and z-BMI. In conclusion, the relationship between screen time and BMI appears to be mediated by increased energy intake, primarily in the form of higher carbohydrate intake. It is possible that reducing time spent watching TV and playing video games may reduce food intake and help promote dietary adherence needed for weight management in obese adolescents.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00195858.

Effects of Child Care Intervention on Physical Activity and Body Composition

INTRODUCTION

This study evaluated whether intervening with child care providers would increase physical activity (PA) and reduce adiposity in preschoolers.

METHODS

This was a two-arm, parallel group, cluster RCT whereby six child care centers were randomly assigned in equal numbers to intervention (n=40 children) or control (n=43 children). Participants were aged 3-5 years and attended licensed child care centers. Child care providers received two 3-hour train-the-trainer workshops and a training manual at program initiation aimed at increasing structured and unstructured PA through active play. Control child care centers implemented their standard curriculum. PA and sedentary behavior were measured by accelerometry, and body composition was measured using bioelectrical impedance at baseline and 6 months. Data were collected in 2011-2012 and analyzed in April 2015.

RESULTS

Linear mixed-effects modeling showed that at 6 months, children in the intervention group demonstrated greater increases in minutes per preschool day spent in overall PA (22.5 minutes, 95% CI=8.9, 36.1, p=0.002), and light-intensity PA (16.1 minutes, 95% CI=5.2, 26.7, p=0.004), but changes between groups in moderate to vigorous PA did not differ. The intervention group showed greater reductions in body fat percentage (-1.9%, 95% CI=-3.5, -0.3, p=0.023) and fat mass (-0.3 kg, 95% CI=-0.7, -0.1, p=0.018), but groups did not differ on fat-free mass, BMI, or z-BMI.

CONCLUSIONS

Provider-led intervention in child care centers increased preschoolers' PA and reduced adiposity, therefore may represent a viable approach to promoting PA and related health benefits in preschool-aged children.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT02293278.

Future research in weight bias: What next?

The 2015 Canadian Weight Bias Summit disseminated the newest research advances and brought together 40 experts, stakeholders, and policy makers in various disciplines in health, education, and public policy to identify future research directions in weight bias. In this paper we aim to share the results of the Summit as well as encourage international and interdisciplinary research collaborations in weight bias reduction. Consensus emerged on six research areas that warrant further investigation in weight bias: costs, causes, measurement, qualitative research and lived experience, interventions, and learning from other models of discrimination. These discussions highlighted three key lessons that were informed by the Summit, namely: language matters, the voices of people living with obesity should be incorporated, and interdisciplinary stakeholders should be included.

Weight bias reduction in health professionals: a systematic review

Innovative and coordinated strategies to address weight bias among health professionals are urgently needed. We conducted a systematic literature review of empirical peer-reviewed published studies to assess the impact of interventions designed to reduce weight bias in students or professionals in a health-related field. Combination sets of keywords based on three themes (1: weight bias/stigma; 2: obesity/overweight; 3: health professional) were searched within nine databases. Our search yielded 1447 individual records, of which 17 intervention studies satisfied the inclusion criteria. Most studies (n = 15) included medical, dietetic, health promotion, psychology and kinesiology students, while the minority included practicing health professionals (n = 2). Studies utilized various bias-reduction strategies. Many studies had methodological weaknesses, including short assessment periods, lack of randomization, lack of control group and small sample sizes. Although many studies reported changes in health professionals' beliefs and knowledge about obesity aetiology, evidence of effectiveness is poor, and long-term effects of intervention strategies on weight bias reduction remain unknown. The findings highlight the lack of experimental research to reduce weight bias among health professionals. Although changes in practice will likely require multiple strategies in various sectors, well-designed trials are needed to test the impact of interventions to decrease weight bias in healthcare settings.

Body composition and energy intake - skeletal muscle mass is the strongest predictor of food intake in obese adolescents: The HEARTY trial

There has been renewed interest in examining the relationship between specific components of energy expenditure and the overall influence on energy intake (EI). The purpose of this cross-sectional analysis was to determine the strongest metabolic and anthropometric predictors of EI. It was hypothesized that resting metabolic rate (RMR) and skeletal muscle mass would be the strongest predictors of EI in a sample of overweight and obese adolescents. 304 post-pubertal adolescents (91 boys, 213 girls) aged 16.1 (±1.4) years with body mass index at or above the 95th percentile for age and sex OR at or above the 85th percentile plus an additional diabetes risk factor were measured for body weight, RMR (kcal/day) by indirect calorimetry, body composition by magnetic resonance imaging (fat free mass (FFM), skeletal muscle mass, fat mass (FM), and percentage body fat), and EI (kcal/day) using 3 day food records. Body weight, RMR, FFM, skeletal muscle mass, and FM were all significantly correlated with EI (p < 0.005). After adjusting the model for age, sex, height, and physical activity, only FFM (β = 21.9, p = 0.007) and skeletal muscle mass (β = 25.8, p = 0.02) remained as significant predictors of EI. FFM and skeletal muscle mass also predicted dietary protein and fat intake (p < 0.05), but not carbohydrate intake. In conclusion, with skeletal muscle mass being the best predictor of EI, our results support the hypothesis that the magnitude of the body's lean tissue is related to absolute levels of EI in a sample of inactive adolescents with obesity.

Positioning of Weight Bias: Moving towards Social Justice

Weight bias is a form of stigma with detrimental effects on the health and wellness of individuals with large bodies. Researchers from various disciplines have recognized weight bias as an important topic for public health and for professional practice. To date, researchers from various areas have approached weight bias from independent perspectives and from differing theoretical orientations. In this paper, we examined the similarities and differences between three perspectives (i.e., weight-centric, non-weight-centric (health-centric), and health at every size) used to understand weight bias and approach weight bias research with regard to (a) language about people with large bodies, (b) theoretical position, (c) identified consequences of weight bias, and (d) identified influences on weight-based social inequity. We suggest that, despite differences, each perspective acknowledges the negative influences that position weight as being within individual control and the negative consequences of weight bias. We call for recognition and discussion of weight bias as a social justice issue in order to change the discourse and professional practices extended towards individuals with large bodies. We advocate for an emphasis on social justice as a uniting framework for interdisciplinary research on weight bias.

Effects of aerobic training, resistance training, or both on cardiorespiratory and musculoskeletal fitness in adolescents with obesity: the HEARTY trial

The purpose of this study was to examine the effects of aerobic, resistance, and combined exercise training on cardiorespiratory and musculoskeletal fitness in postpubertal adolescents with obesity. After a 4-week supervised moderate-intensity exercise run-in, 304 adolescents aged 14-18 years with body mass index ≥85th percentile were randomized to 4 groups for 22 weeks of aerobic training, resistance training, combined training, or a nonexercising control. All participants received dietary counselling with a maximum daily energy deficit of 250 kcal. Cardiorespiratory fitness (peak oxygen consumption) was measured by indirect calorimetry using a graded treadmill exercise test. Musculoskeletal fitness was measured using the 2003 Canadian Physical Activity Fitness and Lifestyle Appraisal tests (hand grip, push-ups, partial curl-ups, sit and reach, and vertical jump). Muscular strength was assessed using an 8-repetition maximum test on the bench press, seated row, and leg press machines. A greater increase in peak oxygen consumption in the aerobic exercise group (30.6 ± 0.6 to 33.4 ± 0.7 mLO2/kg/min) was measured relative to the control group (30.6 ± 0.5 to 30.9 ± 0.7 mLO2/kg/min) (p = 0.002). Similarly, the number of partial curl-ups increased in the aerobic group (19 ± 1 to 23 ± 1) while no differences were measured in the control group (19 ± 1 to 20 ± 1) (p = 0.015). Increases in muscular strength and number of push-ups were greatest in the resistance group versus the control and combined groups versus the aerobic group (p < 0.05). In conclusion, aerobic training had the strongest effect on cardiorespiratory fitness, while resistance and combined training improved both muscular strength and endurance more than control and aerobic training alone, respectively, in adolescents with obesity.

Screen time is independently associated with health-related quality of life in overweight and obese adolescents

AIM

Excessive screen time and diminished health-related quality of life (HRQoL) are greater problems for obese than nonobese adolescents, but no research has examined the relationship between these two variables. This study examined the association between screen time and HRQoL in overweight and obese adolescents.

METHODS

A sample of 358 overweight and obese adolescents aged 14-18 years were assessed at baseline between 2005 and 2010 as part of the Canadian Healthy Eating, Aerobic and Resistance Training in Youth (HEARTY) trial. We used the Pediatric Quality of Life (PEDS-QL) and other self-report measures to assess HRQoL and screen time, defined as how long the 261 females and 97 males spent viewing TV, using the computer and playing video games.

RESULTS

After adjusting for socio-demographic variables, adiposity, physical activity and diet, screen time duration was associated with reduced overall HRQoL (adjusted r = -0.16, ß = -0.16, p = 0.009) and psychosocial HRQoL (adjusted r = -0.16, ß = -0.18, p = 0.004), but not physical HRQoL. No differences were found between males and females.

CONCLUSION

Screen time was associated with reduced overall and psychosocial HRQoL in overweight and obese adolescents. Future research should determine whether reducing screen time improves overall and psychosocial HRQoL in obese adolescents.

Effects of aerobic training, resistance training, or both on psychological health in adolescents with obesity: The HEARTY randomized controlled trial

OBJECTIVE

To determine the effects of aerobic training, resistance training, and combined training on mood, body image, and self-esteem in adolescents with obesity.

METHOD

After a 4-week prerandomization treatment, 304 postpubertal adolescents (91 males, 213 females) with obesity ages 14-18 years were randomized to 1 of 4 groups for 22 weeks: aerobic training (n = 75), resistance training (n = 78), combined aerobic and resistance training (n = 75), or nonexercising control (n = 76). All participants received dietary counseling, with a daily energy deficit of 250 kcal. Mood was measured using the Brunel Mood Scale. Body image was assessed using the Multiple Body Self-Relations Questionnaire, and physical self-perceptions and global self-esteem were measured using the Harter Physical Self-Perceptions Questionnaire.

RESULTS

Median adherence was 62%, 56%, and 64% in aerobic, resistance, and combined training, respectively. Resistance and combined training produced greater improvements than control on vigor, and resistance training reduced depressive symptoms. All groups improved on body image and physical self-perceptions, but combined showed greater increases than control on perceived physical conditioning, while only resistance training showed greater increases than controls on global self-esteem. Both combined and resistance training demonstrated greater increases in perceived strength than control. Psychological benefits were more related to better adherence and reductions in body fat than changes in strength or fitness.

CONCLUSION

Resistance training, alone or in combination with aerobic training, may provide psychological benefits in adolescents with overweight or obesity, and therefore could be an alternative to aerobic training for some individuals in the biological and psychological management of adolescent obesity.

Perspectives of Canadian fitness professionals on exercise and possible anorexia nervosa

BACKGROUND

Many individuals with eating disorders, including anorexia nervosa (AN), engage in overexercise. Little is known about fitness professionals' perceptions of their responsibilities when interacting with clients with possible AN. The purpose of the current study was to examine Alberta fitness professionals' experiences with clients suspected of having AN, and their views on related ethical issues. Specifically, we aimed to examine (1) their experiences with fitness clients suspected of having AN; (2) their opinions about related ethical responsibilities of fitness professionals; and (3) their views on related training and ethical issues.

METHODS

We administered a 21-item online survey to 143 Canadian fitness professionals about their experiences and perspectives on encountering individuals with possible AN in exercise classes and at their exercise facilities.

RESULTS

Sixty-two percent of respondents had encountered a client they believed had AN. Three-quarters had never received any training on managing clients with AN and felt inadequately prepared for such situations. Although most felt ethically obliged to intervene with such a client, more than two-thirds reported no relevant guidelines in their professional training.

CONCLUSIONS

Many fitness professionals are faced with clients with possible AN, have the desire to help, feel ethically obligated to take action, but do not know what course of action to take, if any. Work is needed to clarify ethical issues and related training needs for certification programs for fitness professionals regarding AN.

Effects of aerobic training, resistance training, or both on percentage body fat and cardiometabolic risk markers in obese adolescents: the healthy eating aerobic and resistance training in youth randomized clinical trial

IMPORTANCE

Little evidence exists on which exercise modality is optimal for obese adolescents.

OBJECTIVE

To determine the effects of aerobic training, resistance training, and combined training on percentage body fat in overweight and obese adolescents.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, parallel-group clinical trial at community-based exercise facilities in Ottawa (Ontario) and Gatineau (Quebec), Canada, among previously inactive postpubertal adolescents aged 14 to 18 years (Tanner stage IV or V) with body mass index at or above the 95th percentile for age and sex or at or above the 85th percentile plus an additional diabetes mellitus or cardiovascular risk factor.

INTERVENTIONS

After a 4-week run-in period, 304 participants were randomized to the following 4 groups for 22 weeks: aerobic training (n = 75), resistance training (n = 78), combined aerobic and resistance training (n = 75), or nonexercising control (n = 76). All participants received dietary counseling, with a daily energy deficit of 250 kcal.

MAIN OUTCOMES AND MEASURES

The primary outcome was percentage body fat measured by magnetic resonance imaging at baseline and 6 months. We hypothesized that aerobic training and resistance training would each yield greater decreases than the control and that combined training would cause greater decreases than aerobic or resistance training alone.

RESULTS

Decreases in percentage body fat were -0.3 (95% CI, -0.9 to 0.3) in the control group, -1.1 (95% CI, -1.7 to -0.5) in the aerobic training group (P = .06 vs controls), and -1.6 (95% CI, -2.2 to -1.0) in the resistance training group (P = .002 vs controls). The -1.4 (95% CI, -2.0 to -0.8) decrease in the combined training group did not differ significantly from that in the aerobic or resistance training group. Waist circumference changes were -0.2 (95% CI, -1.7 to 1.2) cm in the control group, -3.0 (95% CI, -4.4 to -1.6) cm in the aerobic group (P = .006 vs controls), -2.2 (95% CI -3.7 to -0.8) cm in the resistance training group (P = .048 vs controls), and -4.1 (95% CI, -5.5 to -2.7) cm in the combined training group. In per-protocol analyses (≥ 70% adherence), the combined training group had greater changes in percentage body fat (-2.4, 95% CI, -3.2 to -1.6) vs the aerobic group (-1.2; 95% CI, -2.0 to -0.5; P = .04 vs the combined group) but not the resistance group (-1.6; 95% CI, -2.5 to -0.8).

CONCLUSIONS AND RELEVANCE

Aerobic, resistance, and combined training reduced total body fat and waist circumference in obese adolescents. In more adherent participants, combined training may cause greater decreases than aerobic or resistance training alone.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00195858.

The effects of resistance exercise training on body composition and strength in obese prepubertal children

OBJECTIVE

To assess the effects of resistance exercise training on body composition and muscular strength in obese prepubertal children.

DESIGN

Study participants, who were between the ages of 8 and 12 years, met Tanner I (stage) criteria, had a body mass index ≥ 95th percentile for age and sex, were randomized to either high-repetition, moderate-intensity resistance training (n = 12) or to the non-intervention control group (n = 7) for 12 weeks. Exercise training was performed twice a week for 75 minutes per session. Body composition was assessed using dual energy x-ray absorptiometry and muscular strength was evaluated using a 1-repetition-maximum test.

RESULTS

Exercise-group participants attended 98% of the 24 total sessions and showed a significant increase in body weight (57.6± 13.5 vs 59.6± 14.1 kg), height (144.9± 9 vs 146.6± 10.4 cm), lean body mass (32.6± 6.8 vs 34.0± 7.0 kg), lean body mass index (lean body mass in kg/height2; 15.3± 1.6 vs 15.6± 1.5 kg/m2), arm strength (28.4± 5.8 vs 31.2± 6.0 kg), and leg strength (89.4± 31.7 vs 113.4± 34 2 kg) from baseline measures (P < 0.05). Control group participants also showed significant increases in weight, height, and lean body mass from baseline measures (P < 0.05) but not in arm or leg strength. When the changes in participant body composition and muscular strength were compared between the exercise and control groups, significant differences were found in leg lean mass and leg strength (P < 0.05). There were no changes in percent body fat and fat mass index [FM/height2(kg/m2)] in either group.

CONCLUSION

Resistance training increases leg lean mass and leg strength in obese prepubertal youth and may have a positive effect on overall physical activity and health.

A review of randomized controlled trials of aerobic exercise training on fitness and cardiometabolic risk factors in obese adolescents

Aerobic training is the most prescribed exercise modality for the management of pediatric obesity. There is strong evidence that it decreases waist circumference, percent body fat and visceral fat, increases cardiorespiratory fitness, and decreases blood pressure in obese adolescents. However, the independent effects of aerobic exercise training on other cardiometabolic risk factors (ie, insulin resistance markers, plasma lipid levels, and inflammatory markers) are limited and yield inconsistent findings. Our article reviews randomized controlled trials evaluating the effects of aerobic exercise training on body composition, fitness, lipid levels, and insulin resistance in obese adolescents (aged 13-18 years) and outlines future research directions for this population.

Screen viewing and diabetes risk factors in overweight and obese adolescents

BACKGROUND

Sedentary behavior has been associated with deleterious cardiometabolic health indicators in adults, but very little research has examined this relationship in youth.

PURPOSE

To examine the association between the duration and type of sedentary screen behavior with diabetes risk factors (fasting glucose, insulin, homeostasis model-insulin resistance [HOMA-IR], 2-hour postload glucose, hemoglobin A1c) in a sample of overweight and obese adolescents.

METHODS

A cross-sectional study of 307 overweight or obese adolescents aged 14-18 years (90 boys, 217 girls) assessed at baseline of a lifestyle intervention for weight control conducted from 2005 to 2010. Sedentary screen behaviors, defined as hours per day spent watching TV, playing seated video games, recreational computer use, and total screen time were measured by self-report. Data were analyzed using linear regression analyses in 2012.

RESULTS

TV viewing was the only type of sedentary screen behavior associated with elevated diabetes risk factors before and after adjustment for confounders. Specifically, TV viewing remained positively associated with fasting insulin (adjusted r=0.11, β=0.10, p=0.048) and HOMA-IR (adjusted r=0.11, β=0.10, p=0.05) after adjustment for age, gender, waist-to-hip ratio, caloric intake, percentage of intake in carbohydrates, physical activity duration, and physical activity intensity.

CONCLUSIONS

TV watching may be independently associated with an increase in diabetes risk factors in a high-risk sample of overweight and obese adolescents. These findings provide support for interventions designed to reduce time spent watching TV as a possible means to attenuating diabetes risk factors in this high-risk population.

Top 10 practical lessons learned from physical activity interventions in overweight and obese children and adolescents

Physical activity (PA) interventions targeting overweight and obese children and adolescents have shown only modest success, and dropout is an area of concern. Proper design and implementation of a PA intervention is critical for maximizing adherence and thus increasing the overall health benefits from PA participation. We propose practical advice based on our collective clinical trial experience with support from the literature on best practices related to PA interventions in overweight and obese children and adolescents. The top 10 lessons learned are (i) PA setting–context is important; (ii) choice of fitness trainer matters; (iii) physical activities should be varied and fun; (iv) the role of the parent–guardian should be considered; (v) individual physical and psychosocial characteristics should be accounted for; (vi) realistic goals should be set; (vii) regular reminders should be offered; (viii) a multidisciplinary approach should be taken; (ix) barriers should be identified early and a plan to overcome them developed; and (x) the right message should be communicated: specifically, what's in it for them? The recommendations in this paper can be used in other pediatric PA programs, physical education settings, and public health programs, with the hope of decreasing attrition and increasing the benefits of PA participation to promote health in children and adolescents.

Overweight and obese teenagers: why is adolescence a critical period?

This paper discusses the critical period of adolescence and its potential role in the development and persistence of obesity. The adolescent years are characteristic of changes in body composition (location and quantity of body fat), physical fitness and decreased insulin sensitivity during puberty. This period of growth and maturation is also marked with behavioural changes in diet, physical activity, sedentary behaviour and psychological health. Physical activity and sport participation decline during adolescence especially in teenage girls, while sedentary behaviour, risk for depression and body esteem issues increase during the teenage years. These physiological and behavioural changes during adolescence warrant the attention of health practitioners to prevent the onset and continuation of obesity throughout the lifespan.