Physical activity level (PAL)
PAL was objectively quantified using a movement sensor (ActiGraph GT3X; ActiGraph, Pensacola, FL, USA). All units were initialized via a computer interface, and data were collected in 15-sec epochs in all three dimensions using specific software (ActiLife 6.9.5 Firmware version). Each adolescent was instructed to wear the movement sensor on the hip (non-dominant side) using an elastic belt for seven consecutive days. The data are presented as the average number of steps per day and the time spent performing moderate-to-vigorous physical activity (MVPA, min*d-1), performing light-intensity physical activity, and sitting (18). Adolescents were considered successfully monitored when they used the accelerometer for at least four days for more than 10 hours per day.