Bone mineral status in adolescent girls: effects of eating disorders and exercise.

PURPOSE: To compare whole-body, lumbar, total spine, and pelvis bone mineral density (BMD), body mass index (BMI), body composition, energy expenditure for physical activity, and dietary intake of adolescents, aged 16-22 years. METHODS: Three study groups included 25 girls with histories of eating disorderd, 25 girls with no histories of eating diso rders who exercised < or = 7 hours/week, and 15 girls with no history of eating disorders who exercised > 7 hours/week. Bone mineral density was measured by dual-energy x-ray absorptiometry (DEXA), body composition by bioelectric impedance and DEXA, energy expenditure by Personal Activity Computer, nutrient intake by 4-day dietary recalls/records, and BMI by measures of height/weight. General linear models, LSM +/- SEM, Student's t-tests, and correlation analyses were used to determine group differences. RESULTS: No significant differences in whole-body, spinal, and pelvis BMD were found among the three groups. Mean body fat (percent) was significantly higher (p =.0001) for the group with histories of eating disorders than other groups. Dietary intakes of adolescents with histories of eating disorders were significantly lower for energy (p =.0001), fat (p =.0001), calcium (p =.0007), vitamin D (p =.0180), and zinc (p =.0057) than those without eating disorder histories who exercised