2.1. Study Participants, Selection and Study Design
A purposive sample of 96 adolescents (49 boys) aged 11–13 years attending two schools in Colombo, Sri Lanka, were recruited after obtaining informed written consent from parents/guardians and assent from children. Sixteen children were consecutively recruited from each age category (11, 12 and 13 years), from each school to represent the national distribution of nutritional status [