title: Muscle-enhancing behaviors among adolescent girls and boys.
abstract: OBJECTIVE
  Media images of men and women have become increasingly muscular, and muscle-enhancing techniques are available to youth. Identifying populations at risk for unhealthy muscle-enhancingbehaviors is of considerable public health importance. The current study uses a large and diverse population-based sample of adolescents to examine the prevalence of muscle-enhancing behaviors and differences across demographic characteristics, weight status, and sports team involvement.
  
  
  METHODS
  Survey data from 2793 diverse adolescents (mean age = 14.4) were collected at 20 urban middle and high schools. Use of 5 muscle-enhancing behaviors was assessed (changing eating, exercising, protein powders, steroids and other muscle-enhancing substances), and a summary score reflecting use of 3 or more behaviors was created. Logistic regression was used to test for differences in each behavior across age group, race/ethnicity, socioeconomic status, BMI category, and sports team participation.
  
  
  RESULTS
  Muscle-enhancing behaviors were common in this sample for both boys and girls. For example, 34.7% used protein powders or shakes and 5.9% reported steroid use. Most behaviors were significantly more common among boys. In models mutually adjusted for all covariates, grade level, Asian race, BMI category, and sports team participation were significantly associated with the use of muscle-enhancing behaviors. For example, overweight (odds ratio = 1.45) and obese (odds ratio = 1.90) girls had significantly greater odds of using protein powders or shakes than girls of average BMI.
  
  
  CONCLUSIONS
  The use of muscle-enhancing behaviors is substantially higher than has been previously reported and is cause for concern. Pediatricians and other health care providers should ask their adolescent patients about muscle-enhancing behaviors.
authors.affiliation: Division of Adolescent Health and Medicine, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA. eisen012@umn.edu
authors.forename: Marla E
authors.initials: ME
authors.lastname: Eisenberg
authors.forename: Melanie
authors.initials: M
authors.lastname: Wall
authors.forename: Dianne
authors.initials: D
authors.lastname: Neumark-Sztainer
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D001828:Body Image / Q000523:psychology; D004044:Dietary Proteins / Q000008:administration & dosage; D019587:Dietary Supplements / Q000706:statistics & numerical data; D004363:Drug Utilization / Q000706:statistics & numerical data; D015444:Exercise / Q000523:psychology; D005247:Feeding Behavior / Q000523:psychology; D005260:Female; D015438:Health Behavior; D006306:Health Surveys / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008910:Minnesota; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000254:growth & development*; D009765:Obesity / Q000453:epidemiology / Q000534:rehabilitation; D050177:Overweight / Q000453:epidemiology / Q000534:rehabilitation; D058573:Performance-Enhancing Substances / Q000008:administration & dosage; D011208:Powders; D012951:Socialization; D013008:Somatotypes / Q000523:psychology; D013256:Steroids / Q000008:administration & dosage
chemical_list: D004044:Dietary Proteins; D058573:Performance-Enhancing Substances; D011208:Powders; D013256:Steroids