Dietary restraint and low bone mass in female adolescent endurance runners.

BACKGROUND: Because disordered eating (DE) has been related to menstrual irregularity (MI) and low bone mineral density (BMD) in some studies of female athletes but not in others, it seems beneficial to assess the DE attitudes and behaviors most associated with these conditions.

OBJECTIVE: We aimed to determine the relation between Eating Disorder Examination Questionnaire (EDE-Q) subscale scores, pathologic behaviors, MI, and low BMD in adolescent female runners.

DESIGN: Participants were 93 female competitive cross-country runners 13-18 y old. The EDE-Q, composed of subscales for weight concern, shape concern, eating concern, and dietary restraint, was used to assess DE. Menstrual history was determined by using a questionnaire derived from a medical history form administered before participation in high school athletics. The International Society for Clinical Densitometry and the World Health Organization criterion of <or=-2 or <or=-1 SD, respectively, was used to categorize runners as having low BMD.

RESULTS: Runners with elevated restraint had a significantly (P<0.001) greater incidence of low BMD than did runners with elevated weight and shape concern. After adjustment for possible confounding variables (including menstrual history), lumbar spine BMD, bone mineral content, and BMD z score values were lowest in runners with elevated restraint. In addition, total-body BMD and total-body BMD z scores were significantly (P<0.05) lower in runners with elevated restraint than in those with elevated weight or shape concern. Elevated EDE-Q scores for weight or shape concern, pathologic behaviors, or any combination of the 3 without concurrent dietary restraint were not significantly associated with low bone mass.

CONCLUSION: These findings suggest that, in adolescent female runners, dietary restraint may be the DE behavior most associated with negative bone health effects.