Objective:To estimate the prevalence of the female athlete triad(disordered eating,menstrual irregularity,and low bone mass)among high school athletes.D esign:Observational cross-sectional study.Setting:High school.Participants:Female athletes(n=170)representing 8 sports were recruited from 6 high school s in southern California.Main Outcome Measures:Disordered eating and menstrual status were determined by interviewer-assisted questionnaires.Bone mineral de nsity was measured by dual-energy x-ray absorptiometry of the hip,spine(L1-L4),and total body.Results:Among all athletes,18.2%,23.5%,and 21.8%met the criteria for disordered eating,menstrual irregularity,and low bone mass,r espectively.Ten girls(5.9%)met criteria for 2 components of the triad,and 2 girls(1.2%)met criteria for all 3 components.Oligomenorrheic/amenorrheic at hletes had higher mean ± SD eating restraint(1.55±1.60 vs 1.04±1.27;P=.02)-and Eating Disorder Exa mination Questionnaire global scores(1.68±1.20 vs 1.33±1.14;P=.03)than eume norrheic athletes.After controlling for age,age at menarche,body mass index,race/ethnicity,and sport type,athletes with oligomenorrhea/amenorrhea had sign ificantly lower mean ±SD bone mineral densities for the trochanter(0.884±0.09 0 g·cm-2)than eumenorrheic athletes(0.933±0.130 g·cm-2;P=0.04).Conclusi ons:The prevalence of the full female athlete triad was low in our sample;howe ver,a substantial percentage of the athletes may be at risk for long-term heal th consequences associated with disordered eating,menstrual irregularity,or lo w bone mass.Preparticipation screening to identify these components should be e ncouraged as a preventive approach to identify high-risk athletes. Objective: To estimate the prevalence of the female athlete triad (disordered eating, menstrual irregularity, and low bone mass) among high school athletes. D esign: Observational cross-sectional study. Letting: High school. Participants: Female athletes ) representing 8 sports were recruited from 6 high school s in southern California. Main Outcome Measures: Disordered eating and menstrual status were determined by interviewer-assisted questionnaires. Bone mineral de nsity was measured by dual-energy x-ray absorptiometry of the hip, Results: Among all athletes, 18.2%, 23.5%, and 21.8% met the criteria for disordered eating, menstrual irregularity, and low bone mass, espectively. Te girls (5.9%) met criteria for 2 components of the triad, and 2 girls (1.2%) met criteria for all 3 components. Oligomenorrheic / amenorrheic at hletes had higher mean ± SD eating restraint (1.55 ± 1.60 vs 1.04 ± 1.27; P = .02) - and Eating Disorder Exa mination Questionnaire global scores (1.68 ± 1.20 vs 1.33 ± 1. 14; P = .03) than eume norrheic athletes. After controlling for age, age at menarche, body mass index, race / ethnicity, and sport type, athletes with oligomenorrhea / amenorrhea had significantly lower mean ± SD bone mineral densities for the Conelusi ons: The prevalence of the full female athlete triad was low in our sample; howe ver, (1998) a substantial percentage of the athletes may be at risk for long-term heal th consequences associated with disordered eating, menstrual irregularity, or lo w bone mass. Preparticipation screening to identify these components should be e ncouraged as a preventive approach to identify high-risk athletes.