Obesity and Emotional Well-Being in Adolescents: Roles of Body Dissatisfaction, Loss of Control Eating, and Self-Rated Health

Transcription

1 Original Article CLINICAL TRIALS AND INVESTIGATIONS Obesity Obesity and Emotional Well-Being in Adolescents: Roles of Body Dissatisfaction, Loss of Control Eating, and Self-Rated Health Kelly Gall 1, Kim van Zutven 2, Joanna Lindstrom 3, Caroline Bentley 2, Kassandra Gratwick-Sarll 2, Carmel Harrison 2, Vivienne Lewis 1, and Jonathan Mond 2,4 Objective: Weak or inconsistent association between obesity and impairment in emotional well-being in population-based samples has led to efforts to identify mediating variables. This study examined the relative importance of body dissatisfaction (BD), loss of control (LOC) eating, and self-rated health (SRH) in mediating the association between obesity and impairment in emotional well-being in a school-based sample of adolescents (boys, n 5 437; girls, n 5 950). Methods: Moderated mediation analysis was employed to assess the relative importance of the putative mediating variables and moderation of mediation effects by sex following the methods suggested by Hayes and coworkers. Results: BD and SRH, but not LOC eating, were found to mediate the association between obesity and impairment in emotional well-being. Stronger mediation effects were observed for BD than for SRH. None of these results was moderated by sex. Conclusions: The findings suggest that it may be important to target BD in obesity prevention and treatment programs in order to reduce the adverse impact of excess body weight on young people s emotional well-being. Obesity (2016) 24, doi: /oby Introduction In children and adolescents, as in adults, population-based studies have found weak or inconsistent associations between obesity and impairment in emotional well-being and psychosocial functioning more generally (1,2). As a consequence, researchers have turned their attention to identifying variables that might indicate which individuals with obesity are most at risk of such impairment (1-4). The goal of this research is to determine whether and to what extent known correlates of obesity, such as body dissatisfaction (BD) and eating-disordered behavior, may mediate the association between obesity and impairment in emotional well-being (1-7). BD may be defined as a negative appraisal of one s weight and/or shape (7). In adolescents, BD is strongly associated with body weight, although this association varies with gender and age (8). BD is also strongly associated with impairment in emotional well-being in adolescents (4) and is an established mediator of the association between obesity and impairment in emotional well-being (3-6). Indeed, evidence suggests that it is BD rather than body weight per se that accounts for impairments in emotional well-being associated with obesity in children, adolescents, and adults (9,10). Although evidence for the role of BD as a mediating variable is stronger in females than in males (5,11,12), findings from recent studies suggest that BD may mediate the association between obesity and impairment in emotional wellbeing in both boys and girls (3,4). These latter findings may reflect increases in the prevalence and adverse impact of BD in males (3,12). In recent years, eating-disordered behavior has also gained attention as a potential mediating variable, in light of increasing awareness that binge, or loss of control (LOC), eating is common in children and adolescents and associated with both obesity and emotional well-being (13,14). Research conducted in young adult women has suggested that LOC eating may play a comparatively minor role in mediating the association between obesity and impairment in emotional well-being when compared with BD (15). The relative importance of LOC eating and BD as mediating variables and sex differences in this regard has not, however, been examined in an adolescent sample, although LOC eating may be more common in girls than boys (12). In children and adolescents, assessment of LOC eating, rather than binge eating, is recommended because the experience of loss of control over eating has been found to be a better index of psychopathology than the amount of food consumed (14). It is well known that physical health and emotional well-being are interrelated (15). Hence, physical health might also be expected to 1 Department of Psychology, University of Canberra, Canberra, Australian Capital Territory, Australia 2 Research School of Psychology, Australian National University, Canberra, Australian Capital Territory, Australia. Correspondence: Jonathan Mond (jonathan.mond@mq.edu.au) 3 Department of Psychology, Stockholm University, Stockholm, Sweden 4 Department of Psychology, Macquarie University, Sydney, New South Wales, Australia. Disclosure: The authors declare no conflicts of interest. Received: 22 June 2015; Accepted: 16 November 2015; Published online 16 February doi: /oby Obesity VOLUME 24 NUMBER 4 APRIL

2 Obesity Obesity and Emotional Well-Being in Adolescents Gall et al. play a role in mediating the association between obesity and impairment in emotional well-being. Physical health impairment has been found to mediate the association between obesity and impairment in emotional well-being in adults (16,17) and obesity has been found to be associated with poorer self-rated health (SRH) in adolescents (18). A population-based study in the United States found that SRH mediated the association between overweight and depressive symptoms in younger (but not older) adolescents (5). Whether the importance of physical health status as a mediating variable may differ by sex in young people is unclear. There is some evidence that BD is a more potent mediator of the association between obesity and mental health impairment than binge eating in young adult women (16,19) and that SRH is a more potent mediator in boys than in girls (5). To the authors knowledge, only one study has examined the relative importance of BD, binge or LOC eating, and physical health status in mediating the association between obesity and impairment in emotional well-being (17). In a general population sample of women and men aged years, van Zutven et al. (17) found that BD and SRH, but not LOC eating, mediated the association between obesity and impairment in emotional well-being and that this was the case for both men and women. Further, BD was a stronger mediator than SRH in men and a trend in this direction was observed in women. Whether and to what extent these findings might be replicated in young people would be of interest from a health promotion perspective, for example, in informing whether obesity and mental health prevention and early intervention efforts should prioritize BD, eating-disordered behavior, or physical health. The primary goal of the current research was, therefore, to determine the relative importance of BD, LOC eating, and physical health status in mediating the association between obesity and impairment in emotional wellbeing in adolescents. A secondary aim of the research was to examine the possible moderation of any observed mediation effects by sex. Our only a priori hypothesis was that BD would be a potent mediator of the association between obesity and impairment in girls. Method Study design and recruitment of participants The study methods have been detailed elsewhere (20). In brief, male and female students attending twelve secondary schools in the Australian Capital Territory (ACT) region (population of approximately 375,000 in 2012) were recruited for a study of BD, eatingdisordered behavior and mental health literacy. The schools varied in terms of type (Government, Independent, and Catholic), location, and the number and age and sex distributions of students. All students in classes selected for participation who attended class on the day(s) assigned for data collection were invited to complete a printed, self-report questionnaire, in their classrooms, under the supervision of a teacher and one or more members of the research team. The questionnaire included measures of BD, SRH, eating disorder features (including LOC eating), general psychological distress, quality of life, and socio-demographic information (age, sex, country of birth, first language). Body mass index (BMI) (kg/m 2 ) was derived from self-reported height and weight. The study was presented as an opportunity for schools to promote eating disorders mental health literacy and no remuneration was provided. School principals and students provided consent whereas parents were given the opportunity to opt-out. Approval for the project was granted by the Australian National University Human Research Ethics Committee, the ACT Department of Education and Training and the Canberra, and Goulburn Catholic Education Office. Completed questionnaires were received from 1,749 students, a participation rate of 78.7%. Data was excluded for nine participants who were less than 12 years of age or greater than 18 years and a further 70 participants (4.0%) whose responses included unacceptably high levels of missing or corrupt data. The final sample therefore comprised 1,670 students aged years. Of these, 1,135 (68.0%) were females (7.8% of all female ACT secondary school students), 531 were males (3.6% of all male ACT secondary school students), and 4 students did not indicate their gender. Consistent with the demographic profile of the ACT region (20), most participants were born in Australia (88.3%) and had English as a first language (90.4%). The mean (SD) ages of male and female participants were (1.70) years and (1.63) years, respectively. The 481 male participants (90.6%) who provided details of height and weight had a mean (SD) BMI of (3.58). The 1,007 female participants (88.7%) who provided details of height and weight had a mean (SD) BMI of (3.57). Study measures Weight status. Participants were classified into four weight categories ( underweight : 5th percentile; normal weight : 5th to 84th percentiles; overweight : 85th to 94th percentiles; and obesity : 95th percentile) based on the age- and sex-specific BMI cut-points recommended by the United States Centers for Disease Control and Prevention (CDC) (21). Since we were interested specifically in the associations between obesity and emotional well-being, participants in the underweight and overweight categories were excluded and obesity was coded as a dichotomous variable. Physical health status (SRH). SRH was assessed with the single item In general, would you say your health is...? This item required participants to rate their overall health during the past four weeks on a 5-point, Likert-type scale ranging from 1 (excellent) to5 (poor). Responses to this item have been found to be strongly predictive of more objective measures of health status, such as medical morbidity, health service utilization, and mortality (22,23). BD. BD was assessed using the Weight/Shape Concerns Subscale of the Eating Disorder Examination Questionnaire (EDE-Q), a 12- item measure that assesses participants dissatisfaction with weight and shape and related constructs, such as the overvaluation of weight or shape, during the past 28 days (24). It has been widely used in population-based studies of both adults and adolescents, including research conducted by the authors, and has good psychometric properties (19). Cronbach s alpha in the present study sample ranged from 0.70 (Eating Concerns) to 0.94 (global score) for male participants and from 0.84 (Eating Concerns) to 0.97 (global score) for female participants. LOC eating. LOC eating was assessed with two items of the EDE-Q that assess the occurrence and frequency of eating disorder behaviors, namely: During the past four weeks, how many times 838 Obesity VOLUME 24 NUMBER 4 APRIL

3 Original Article CLINICAL TRIALS AND INVESTIGATIONS Obesity TABLE 1 Demographic characteristics of participants by weight status and sex Girls Boys (n 5 919) (n 5 31) (n 5 409) (n 5 28) Mean (SD) Mean (SD) t p Mean (SD) Mean (SD) t p Age (years) (1.62) (1.29) (1.70) (1.39) BMI (kg/m 2 ) (2.19) (3.23) < (2.25) 29.3 (3.51) <0.001 % % v p % % v 2 p Australian born English first language have you eaten what other people would think was a very large amount of food given the situation and felt like you had lost control of your eating at the time? ; and During the past four weeks, how many times have you eaten what other people would think was a normal or small amount of food given the situation and felt like you had lost control of your eating at the time? The number of episodes of LOC eating during the past four weeks was calculated as the sum of responses to these items. Emotional well-being. Emotional well-being was assessed using the Kessler (10-item) Psychological Distress Scale (K-10), a widelyused measure that was developed to screen for anxiety and affective disorders in epidemiological studies (25,26). It also is used as an outcome measure for individuals treated in community mental health services and for routine population mental health monitoring (25). Participants indicate how often they experienced each of 10 symptoms of anxiety or depression during the past four weeks. For example: In the past four weeks (28 days), how often have you felt so sad that nothing could cheer you up, and In the past four weeks (28 days), how often did you feel so nervous that nothing could calm you down? Responses are scored on a five-point, Likert-type scale ranging (1 5 none of the time to 5 5 all of the time). Total scores range from 10 to 50, with higher scores indicating higher levels of distress. Scores of are considered to be in the low risk range, scores of medium risk, and scores of high risk (26). The K-10 has very good psychometric properties, including high internal consistency and demonstrated validity in predicting clinically significant levels of distress in general population samples of adults and adolescents (25,26). Cronbach s alpha for male and female participants in the present study sample was 0.87 and 0.91, respectively. Statistical analysis Missing data for BMI (and CDC categories) (10.6%) were found to be missing at random in preliminary analysis. Missing BMI data was imputed using a HOTDECK (27) bootstrapping procedure which assigns responses based on sampling of the closest participants who match the missing case on BMI-related deck variables in the randomly sorted data set. Non-parametric (Mann-Whitney U) tests were used to compare adolescents at normal and obese weights, stratified by sex, on each of the study variables. Correlations between study variables were calculated using Spearman s rho coefficient. Mediation and moderated-mediation (conditional process) analyses, including comparison of mediation effects, were conducted using the methods described by Hayes (28) and using the associated PROCESS custom dialogue. This approach uses bootstrapping for the calculation of confidence intervals, which improves the precision of parameter estimates and reduces Type 1 error relative to normal theory approaches. Further, this approach does not require a statistically significant association between the independent and dependent variables as a prerequisite for mediation analysis. These methods were considered appropriate for the current study given the relatively small number of adolescents with obesity. Heteroskedasticityconsistent standard errors were used for all of the main moderation and mediation analyses. Mean centering was used in the main analyses for interaction effects, as were 95% bias corrected bootstrapped confidence intervals based on 10,000 bootstrap samples. The potential for obesity itself to act as a moderator of the indirect effects of the three putative mediating variables on emotional well-being was tested and excluded prior to conducting the main analyses. Age, country of birth, first language, and school type were included as covariates in all multivariable analyses. All analyses were conducted using SPSS version 22, a significance (alpha) level of 0.05 was employed for all analyses, and all tests were two-tailed. Results Descriptive statistics Fifty-nine adolescents with obesity (males: 28; females: 31) and 1,328 normal-weight (males: 409; females: 919) participants were retained for the analysis. Girls with obesity were more likely to be born in Australia and have English as a first language than normalweight girls whereas country of birth and first language did not differ between boys with obesity and normal weight (Table 1). Girls with obesity had higher levels of general psychological distress and BD, and poorer SRH, than girls of normal weight (Table 2). Boys with obesity had higher levels of BD than normal-weight boys whereas differences between these two groups with respect to levels of general psychological distress and SRH did not reach statistical significance. The prevalence of LOC eating did not differ by weight status in boys (obesity 14.28%, normal weight 11.7%; v , p ) whereas this difference approached statistical significance in girls (obesity 48.49%, normal weight 32.64%; v , p ). As can be seen in Table 3, there were generally small to moderate positive correlations between study variables. Obesity VOLUME 24 NUMBER 4 APRIL

4 Obesity Obesity and Emotional Well-Being in Adolescents Gall et al. TABLE 2 Median scores and interquartile range (IQR) for measures of body dissatisfaction (BD; weight/shape concerns), selfrated health and general psychological distress, and frequency of loss of control (LOC) eating by weight status and sex Girls Boys (n 5 919) (n 5 31) (n 5 409) (n 5 28) Median (IQR) Median (IQR) Z p r a Median (IQR) Median (IQR) Z p r a Psychological distress b (11) 24.5 (16.75) (7.00) (9.00) Weight/shape concerns (BD) c 2.00 (3.17) 3.33 (3.00) (0.83) 1.98 (2.83) Self-rated health d 2.00 (1.00) 3.00 (2.00) (1.00) 2.50 (1.00) % % v 2 p % % v 2 p Self-rated health (low) e LOC eating f a Effect size: r. b Kessler 10-item Psychological Distress Scale (K-10) (25). c Eating Disorder Examination Questionnaire (EDE-Q) Weight/Shape Concerns subscale (24). d Self-rated health: In general, would you say your health is... poor, fair, good, very good, excellent? (higher scores indicate poorer perceived health). e Low self-rated health coded as fair or poor. f Percentage (%) of participants reporting any episodes of LOC eating in the past 28 days. Moderated mediation analysis Sex did not moderate any of the mediating pathways and there was no mediating effect of LOC eating. Hence the theoretical model was revised to exclude moderation by sex and mediation by LOC eating, results are detailed in Table 4. After accounting for the combined effects of SRH and BD (total effects), the significant association between obesity and impairment in emotional well-being (b , p ) became clearly non-significant (b , p ). Mediating (indirect) effects of both BD (b , p < 0.000) and SRH (b , p ) were observed with all confidence intervals entirely above zero. After controlling for covariates, the unique indirect effect of SRH was weaker than that of BD (b , S b ) with confidence intervals entirely below zero (22.00 to ). Discussion Summary of main findings In a general population sample of adolescents, we sought to determine the relative importance of BD, LOC eating, and SRH as mediators of the association between obesity and impairment in emotional wellbeing, as well as the possible moderation of mediation effects by sex. The key findings were threefold. First, for both boys and girls, BD and SRH, but not LOC eating, mediated the association between obesity and impairment in emotional well-being. Second, the mediating effects of BD were stronger than those of SRH. Third, sex did not moderate the associations between obesity and impairment in emotional wellbeing either directly or indirectly through either BD or SRH. Evidence that obesity may be conducive to impairment in emotional well-being by virtue of its association with BD and physical health impairment is consistent with and extends findings from previous research in adult (4,16,17) and adolescent (4,9) samples. The finding that BD was a stronger mediator of the association between obesity and impairment in emotional well-being than SRH, for both boys and girls, is notable and consistent with findings from a recent study in adults (17). More generally, the current findings are consistent with a growing body of evidence suggesting that BD may exhibit a greater influence on mental health outcomes among individuals with obesity than other potential mediating variables (6,9,17,29). The finding that there was no moderation of the direct effects of obesity on emotional well-being by sex also is notable. It may be that sex differences in the effects of obesity on emotional well-being are diminishing as BD is increasing in boys (4,12). While the direct association between obesity and (impaired) emotional well-being reached statistical significance in girls in the current study, the small number of boys with obesity limited statistical power to detect associations involving this subgroup. The small effect sizes observed for the direct effects on obesity on emotional well-being in the current study, for both girls and boys, serve as a reminder that, in the absence of other factors, obesity is associated with little or no impairment in emotional well-being (4,30). Implications Currently, interventions and treatment guidelines for obesity in adolescents are focused on achieving weight loss through encouraging TABLE 3 Correlations between study variables (data for boys is shaded) Obesity K-10 WSC LOC SRH Obesity * Psychological 0.07** * 0.27* 0.17* distress (K-10) Weight/shape 0.11* 0.52* * 0.14* concerns (WSC) Loss of control eating (LOC) 0.06** 0.38* 0.52* * Self-rated health (SRH) 0.11* 0.31* 0.26* 0.16** - *Correlation is significant at 0.01 level (two-tailed). **Correlation is significant at the 0.05 level. 840 Obesity VOLUME 24 NUMBER 4 APRIL

5 Original Article CLINICAL TRIALS AND INVESTIGATIONS Obesity TABLE 4 Mediation analysis of the effects of weight/shape concerns and self-rated health in mediating the associations between obesity and impairment in emotional well-being (general psychological distress) b(s b ) a T p CI Z p e Obesity b Weight/shape concerns (0.228) (0.611, 1.507) Self-rated health (0.136) (0.157, 0.693) General psychological distress c Weight/shape concerns (0.149) (1.352, 1.936) Self-rated health (0.233) (0.909, 1.822) General psychological distress d Total effect (1.106) (0.235, 4.576) Direct effect (0.975) (21.830, 1.996) Indirect effect: Weight/shape concerns (0.410) (0.997, 2.621) Indirect effect: Self-rated health (0.217) (0.220, 1.088) a b 5 unstandardized regression coefficient; s b 5 standard error of b. b Obesity as a predictor of the putative mediating variables (weight/shape concerns, loss of control [LOC] eating). c Putative mediating variables as predictors of general psychological distress. d The total effect indicates the association between obesity and (regression of obesity on) the outcome variable without any mediating variables in the model but including covariates; the direct effect indicates the association between obesity and the outcome variable with all mediating variables in the model as well as covariates. Indirect effects for weight/shape concerns and health status indicate the indirect (mediating) effects of the variable in question controlling for other mediating variables. Covariates included in all analyses were: age, Australian born, first language, LOC eating, gender. e Significance of the indirect (mediation) effect according to Sobel s test (provided for comparison purposes only) (4). healthy food choices, portion control, and regular, appropriate physical activity (31,32). In population-based prevention trials, body image is typically assessed only as a secondary variable, i.e., to assess for potential adverse effects caused by these programs focus on body weight (33). The current findings suggest that programs seeking to reduce the adverse impact of obesity on adolescents health and well-being may need to target BD in addition to diet and physical activity as outcome variables. As BD during adolescence is associated with greater unhealthy weight-management practices, binge eating, and weight gain, later in life (34), interventions specifically targeting BD early in life may reduce the risk that adverse health outcomes associated with adolescent obesity persist into adulthood. This warrants empirical investigation. Multi-component programs that seek to integrate obesity and eating disorders prevention messages have been developed for adolescent girls (35). Adaptation of such programs for implementation in mixed-sex samples would be valuable. In terms of implications for the clinical management of obesity in adolescents, the findings suggest that specifically targeting BD may similarly be beneficial in improving treatment outcomes. Study limitations and other methodological considerations The current findings should be interpreted in light of several methodological limitations. First, this was a cross-sectional study. Although the findings are consistent with obesity indirectly affecting emotional well-being, emotional well-being may also affect body weight or associations may exist in both directions. Second, all variables were assessed by means of self-report measures. The use of self-report measures of constructs such as BD and LOC eating may be particularly problematic in adolescents (13). There may have been a tendency for adolescents with obesity to underestimate their weight and for LOC eating to be underestimated more generally (13,36). This may explain, in part, the small number of boys with obesity who reported LOC eating despite the relatively large sample size. However, LOC eating does not appear to be an important mediator of the association between obesity and mental health impairment in either boys or girls. Third, SRH was used as a proxy for physical health status in the current study. Although this was reasonable (23,24), the inclusion of additional, more objective measures of health status in future research would be of interest (37). Fourth, aside from error inherent in the calculation of BMI based on self-reported height and weight, weight-circumference to height ratio may provide a more accurate indication of body adiposity amongst adolescents (38). Fifth, not all potentially important mediating variables were assessed. Weight-related teasing, which is known to be associated with both BD and impairment in emotional well-being (39), is one such variable. Finally, the fact that the research was conducted in a relatively affluent, urbanized region with relative underrepresentation of individuals with obesity may limit generalizability to more diverse populations. With respect to this final limitation, ecological validity will have been enhanced through the recruitment of a diverse cross-section of schools in the region sampled and high rates of within-school participation. In this regard it might be noted that the prevalence of body dissatisfaction and LOC eating in the current study sample were similar to those reported for boys and girls in a comparable sample of adolescents in the United States (14,20). Additional strengths of the current study were the relatively large sample size, the assessment of three potentially important mediating variables, and the use of analytic procedures that permitted assessment of the relative importance of mediation effects and the possible moderation of these effects by sex. In sum, the findings of the current study suggest that BD and physical health status, but not LOC eating, mediate the association Obesity VOLUME 24 NUMBER 4 APRIL

6 Obesity Obesity and Emotional Well-Being in Adolescents Gall et al. between obesity and impairment in emotional well-being in both boys and girls and that the role of BD may be particularly important. Specifically targeting BD in the prevention and clinical management of obesity may be important in reducing the adverse impact of excess body weight on young people s emotional well-being. O VC 2016 The Obesity Society References 1. Loth KA, Mond J, Wall M, Neumark-Sztainer D. Weight status and emotional wellbeing: longitudinal findings from project EAT. J Pediatr Psychol 2011;36: Bolton K, Kremer P, Rossthorn N, et al. The effect of gender and age of the association between weight status and health-related quality of life in Australian adolescents. BMC Public Health 2014;14: Chaiton M, Sabiston C, O Loughlin J, McGrath JJ, Maximova K, Lambert M. A structural equation model relating adiposity, psychosocial indicators of body image and depressive symptoms among adolescents. Int J Obes 2009;33: Mond JM, van den Berg P, Boutelle K, Hannan P, Neumark-Sztainer D. Obesity, body dissatisfaction, and emotional well-being in early and late adolescence: findings from the project EAT study. J Adolesc Health 2011;48: Needham BL, Crosnoe R. Overweight status and depressive symptoms during adolescence. J Adolesc Health 2005;36: Franklin J, Denyer G, Steinbeck KS, Caterson ID, Hill AJ. Obesity and risk of low selfesteem: a statewide survey of Australian children. Pediatrics 2006;118: Goldschmidt AB, Aspen VP, Sinton MM, Tanofsky- Kraff M, Wilfley DE. Disordered eating attitudes and behaviors in overweight youth. Obesity 2008;16: Calzo JP, Sonneville KR, Haines J, Blood EA, Field AE, Austin SB. The development of associations among BMI, body dissatisfaction, and weight and shape concern in adolescent boys and girls. J Adolesc Health 2012;51: Jansen W, van de Looij-Jansen PM, de Wilde EJ, Brug J. Feeling fat rather than being fat may be associated with psychological well-being in young dutch adolescents. J Adolesc Health 2008;42: Muennig P, Jia H, Lee R, Lubetkin E. I think therefore I am: perceived ideal weight as a determinant of health. J Public Health 2008;98: Gray L, Leyland AH. Overweight status and psychological well-being in adolescent boys and girls: a multilevel analysis. Eur J Public Health 2008;18: Mitchison D, Mond JM. Epidemiology of eating disorders, eating-disordered behaviour, and body image disturbance in males: A narrative review. J Eat Disord 2015;3: Sonneville KR, Horton NJ, Micali N, et al. Longitudinal associations between binge eating and overeating and adverse outcomes among adolescents and young adults: does loss of control matter? JAMA Pediatrics 2013;7: Tanofsky-Kraff M, Shoemaker LB, Olsen C, et al. A prospective study of pediatric loss of control eating and psychological outcomes. JAP 2011;120: Patel M, Saxena P, Maj V, et al. No health without mental health. Lancet 2007;370: Mond JM, Hay P, Rodgers B, Owen C, Bayne BT, Kennedy RL. Obesity and impairment in psychosocial functioning women: the mediating role of eating disorder features. Obesity 2007;15: van Zutven K, Mond J, Latner JD, Rodgers B. Obesity and psychosocial impairment: mediating roles of health status, weight/shape concerns and binge eating in a community sample of women and men. Int J Obes 2015;39: Knoesen NP, Mancuso SG, Thomas S, Komesaroff P, Lewis S, Castle DJ. Relationship between severity of obesity and mental health: An Australian community survey. Asia-Pac Psychiatry 2012;4: Jansen A, Havermans R, Nederkoorn C, Roefs A. Jolly fat or sad fat? Subtyping non-eating disordered overweight and obesity along an affect dimension. Appetite 2008;51: Mond JM, Hall A, Bentley C, Harrison C, Gatwick-Sarli K, Lewis V. Eatingdisordered behavior in adolescent boys: eating disorder examination questionnaire norms. Int J Eat Disord 2014;47: Kuczmarski RJ, Ogden CL, Guo S, et al CDC growth charts for the United States: methods and development. Vital Health Stat ; Idler EL, Benyamini Y. Self-rated health and mortality: a review of twenty-seven community studies. J Health Soc Behav 1997;38: DeSalvo KB, Fan VS, McDonell MB, Fihn SD. Prediciting mortality and healthcare utilisation with a single question. Health Serv Res 2005;401: Fairburn CG, Beglin SJ. Assessment of eating disorders: interview of self-reported questionnaire? Int J Eat Disord 1994;16: Kessler RC, Andrews G, Colpe LJ, Hiripi E, Mroczek DK, Normand SLT. Short screening scales to monitor population prevalences and trends in non-specific psychological distress. Psychol Med 2002;32: Andrews G, Slade T. Interpreting scores in the Kessler Psychological Distress Scale (K10). Aust N Z J Public Health 2001;25: Myers TA. Goodbye listwise deletion: presenting hot deck imputation as an easy and effective tool for handling missing data. Commun Methods Meas 2011;5: Hayes AF. Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-Based Approach. New York: Guilford; Mond JM, Hay PJ, Rodgers B, Owen C. Comparing the health burden of eating disordered behaviour and overweight in women. J Women s Health 2009;20: Roberts RE, Hao DT. Obesity has few effects on future psychosocial functioning of adolescents. Eat Behav 2013;14: Sargent GM, Pilotto LS, Baur LA. Components of primary care interventions to treat childhood overweight and obesity: a systematic review of effects. Obes Rev 2011;12: Haynos AF, O Donohue WT. Universal childhood and adolescent obesity prevention programs: review and critical analysis. Clin Psychol Rev 2012;32: NHMRC. Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults, Adolescents and Children in Australia. Melbourne: National Health and Medical Research Council of Australia; Neumark-Sztainer D, Paxton SJ, Hannan PJ, Haines J, Story M. Does body satisfaction matter? Five-year longitudinal associations between body satisfaction and health behaviors in adolescent females and males. J Adolesc Health 2006;39: Neumark-Sztainer DR, Friend SE, Flattum CF, et al. New moves preventing weight-related problems in adolescent girls: a group-randomized study. Am J Prev Med 2010;39: Khambalia A, Hardy l, Bauman A. Accuracy of weight perception, lifestyle behaviours and psychological distress among overweight and obese adolescents. J Pediatr Child Health 2012;48: Boardman JD. Self-rated health among U.S. adolescents. J Adolesc Health 2005;38: Brambilla P, Bedogni G, Heo M, Pietrobelli A. Waist circumference-to-height ration predicts adiposity better than body mass index in children and adolescents. Int J Obes 2013;37: Lampard AM, MacLehose RF, Eisenberg ME, Neumark-Sztainer D, Davison KK. Weight-related teasing in the school environment. Associations with psychosocial health and weight control practices among adolescent boys and girls. J Youth Adolesc 2014;43: Obesity VOLUME 24 NUMBER 4 APRIL