Relationship between calcium intake and body mass index in adolescents

Epidemiologic and experimental data support thee possibility that dietary calcium intake plays a role in human body weight regulation. The aim of the present study was to evaluate calcium intake and its relationship with body mass index (BMI) in adolescents. Weight, height, 3-day food record and a food frequency questionnaire were collected among all adolescents participants at the Outpatient Clinic for Adolescents at the Federal University of Sao Paulo between 2001 and 2003. The statistical analysis comprised Chi-square, Student's T-test, Pearson correlation and linear regression. One-hundred and twenty-one adolescents were studied (62.8% female), with a mean age of 14.9 +/- 2.2 years old. Mean energy and calcium intakes were 1729.9 +/- 557.8 kcal/day and 598.2 +/- 287.9 mg/day respectively, with no significant statistical differences between sex or age. Almost ninety-eight percent of adolescents presented a mean calcium intake lower than proposed values. Calcium intake adjusted for energy presented a significant negative correlation with body weight (r=-0.194, p=0.03) and BMI (r=-0.185, p=0.04). Furthermore, adolescents in the lowest quartile of calcium intake presented higher BMI (29.7 +/- 7.4 kg/m2) than adolescents in the highest calcium quartile. These results indicated a dietary calcium intake lower than recommendations for this life stage, and a contribution of this mineral in the body mass index.