title: Inaccurate weight perception is associated with extreme weight-management practices in U.S. high school students.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  WPA, overassessment, and underassessment were determined by comparing self-reported BMI and weight perception among U.S. high school students in the 2009 National Youth Risk Behavior Survey. BMI was classified as follows: underweight (<5th percentile), healthy weight (5th to <85th), overweight (≥85th to <95th), and obese (≥95th). WPA was considered inaccurate if BMI and weight perception were discordant. 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). EWPs included ≥1 of fasting, use of diet pills, or purging/laxative use. Logit models were fitted for different BMI sex strata.
  
  
  RESULTS
  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. In turn, 11.4% and 17.6% of accurate and inaccurate assessors engaged in EWPs, respectively. After adjustment, underweight girls who overassessed their weight had 12.6 times higher odds of EWPs (95% confidence interval 3.4-46.6). Moreover, there were elevated odds of EWPs among healthy weight students who overassessed their weight.
  
  
  CONCLUSIONS
  Overassessing healthy weight students and underweight girls had higher odds of ≥1 EWPs, likely related to an unhealthy desire to lose weight. 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.
authors.affiliation: *Department of Epidemiology and Public Health †Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Chadi
authors.initials: C
authors.lastname: Ibrahim
authors.forename: Samer S
authors.initials: SS
authors.lastname: El-Kamary
authors.forename: Jason
authors.initials: J
authors.lastname: Bailey
authors.forename: Diane M
authors.initials: DM
authors.lastname: St George
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D001828:Body Image; D015992:Body Mass Index; D001835:Body Weight; D002400:Cathartics; D005215:Fasting; D001068:Feeding and Eating Disorders / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D054368:Laxatives; D008297:Male; D009765:Obesity / Q000523:psychology*; D050177:Overweight; D004364:Pharmaceutical Preparations; D012016:Reference Values; D012307:Risk Factors; D057566:Self Report; D013334:Students; D013851:Thinness / Q000523:psychology; D014481:United States; D014892:Weight Perception
chemical_list: D002400:Cathartics; D054368:Laxatives; D004364:Pharmaceutical Preparations