Bone mineral density, body composition, and food intake of adolescent runway models

To evaluate the bone mineral density (BMD) and to relate it to the food intake and body composition of adolescent runway models.

Cross-sectional study evaluating 33 models and 33 non-models aged from 15 to 18 years, paired by age and body mass index (BMI). BMD of spine (L1-L4) was evaluated using the dual-energy X-ray absorptiometry technique (Lunar DPX Alpha), and body composition was assessed by means of plethysmography. Food intake was evaluated by a 3-day-food record.

The subjects' mean age was 16.75+/-1.04 years, and 24% had BMI below ideal value for their age. BMD values (g/cm2) were similar between models (1.108+/-0.080) and non-models (1.096+/-0.102) (p > 0.05), and 6% of the participants had low BMD for age. We found that the mean energy intake was lower among models as compared to non-models (1,480.93+/-582.95 vs. 1,973.00+/-557.63 kcal) (p < 0.05) and that most of the adolescents in both groups presented an inadequate consumption of micronutrients, with emphasis to the low calcium intakes. There was only significant correlation between BMD and lean body mass (kg) (r = 0.362 for models and r = 0.618 for non-models) (p < 0.05).

Although no association was found between BMD, BMI, and intake of nutrients which are important for the bone mineralization process, inadequacies of food intake have an adverse influence on the acquisition of bone mass, which is more effective at this stage of life.