Distribution of anthropometric and behavioral characteristics at 13 and 17 years of age according to bone mineral density (BMD) z-scores at 13 and 17 years of age.

P-values were calculated using chi-square of Fisher's exact tests, as appropriate (for the comparisons between proportions), or using Student's t-test (for the comparisons of means).*Behavioral clusters defined using the following variables: sports activities, fruit intake, sleeping hours, time spent in sedentary activities, tobacco and alcohol use [23]. Adolescents were classified in one of three following groups according to behavioral aggregation: healthiest (cluster 1), intermediate (cluster 2) and least healthy (cluster 3).†Z-score −1.0 cutoff corresponded to 0.303 g/cm2 at 13 and 0.386 g/cm2 at 17 years of age.‡Estimates are not presented because exposures are behaviors which took place in late adolescence while the outcome (BMD) refers to early adolescence.