The overall goal of the YRBS is to monitor health and risk behaviors in youth. The design of the YRBS, a cross-sectional survey, has been described in detail elsewhere (7,8). We analyzed the 2009 national YRBS, which reports data from September 2008 to December 2009 (7). In the present study, we aimed to determine the prevalence of accurate and inaccurate weight perception among US high school students in all BMI categories investigate the association of WPA with EWPs and determine the effect of sex, high school grade, and/or race/ethnicity on the association between WPA and EWPs.

Because both sex and race/ethnicity have been previously shown to differentially influence WPA (6), it is of interest to investigate the effects of these variables on this association. Therefore, determining the association of WPA with EWPs in different weight groups is warranted. It is also important to look at EWPs as a group of behaviors rather than considering fasting, diet pill intake, or laxative use independently because these practices all represent EWPs and stem from similar weight-losing intentions.

Higher degrees of inaccuracy may indicate a distorted sense of reality and underlying psychopathology. Because eating disorders commonly start out as supposedly innocent dieting behaviors (5), examining adolescents’ sense of accurate weight perception may allow earlier recognition of EWPs and associated eating disorders. Although it is of obvious health relevance to examine the association of WPA with EWPs in underweight adolescents because of eating disorders, it is also important to explore these associations in healthy and overweight adolescents. To our knowledge, only 1 study has investigated the association between weight perception accuracy (WPA) and EWPs, although its focus was on overweight adolescents, rather than students of all body mass index (BMI) percentile categories (4). These extreme weight-management practices (EWPs) may indicate eating disorders such as bulimia nervosa or anorexia nervosa, which are common chronic illnesses of childhood among all age groups (2,3), with the crude mortality rate for each being approximately 18% (2,3). A group of these students resort to extreme behaviors such as fasting for >24 hours, taking nonprescription diet supplements, and purging to lose weight (1). The present study demonstrates a need to further educate clinicians on WPA and its relation to EWPs even among those of healthy weight who may be seen as not at risk.Īccording to the 2009 Youth Risk Behavior Survey (YRBS) of the Centers for Disease Control and Prevention (CDC), close to half of all high school students in the United States are trying to lose weight (1). Overassessing healthy weight students and underweight girls had higher odds of ≥1 EWPs, likely related to an unhealthy desire to lose weight. Moreover, there were elevated odds of EWPs among healthy weight students who overassessed their weight. After adjustment, underweight girls who overassessed their weight had 12.6 times higher odds of EWPs (95% confidence interval 3.4–46.6). In turn, 11.4% and 17.6% of accurate and inaccurate assessors engaged in EWPs, respectively. In the final sample of 14,722 US high school students with complete data, 20.2%, 85.7%, 5.8%, and 80.9% of those who were underweight, healthy weight, overweight, and obese, inaccurately assessed their weight, respectively. Logit models were fitted for different BMI sex strata. EWPs included ≥1 of fasting, use of diet pills, or purging/laxative use. Overassessors thought they were heavier than they were (among underweight/healthy groups) underassessors thought they were lighter than they were (among healthy/overweight/obese groups). WPA was considered inaccurate if BMI and weight perception were discordant. BMI was classified as follows: underweight (<5th percentile), healthy weight (5th to <85th), overweight (≥85th to <95th), and obese (≥95th).

WPA, overassessment, and underassessment were determined by comparing self-reported BMI and weight perception among US high school students in the 2009 National Youth Risk Behavior Survey. The objective of the present study was to examine whether adolescents’ weight perception accuracy (WPA) was associated with extreme weight-management practices (EWPs) in differing body mass index (BMI) categories.

Inaccurate perception definition