Anthropometric, demographic and socio-economic data

Weight and height measurements were performed according to standard procedures⁽²⁸⁾. Body weight was measured to the nearest 0·1 kg with a portable digital scale (PP 180, Marte Científica). Height was measured to the nearest 1 mm with a stadiometer (AlturExata). Age- and sex-specific BMI Z-scores were calculated according to the WHO for children and adolescents aged 5–19 years⁽²⁹⁾. The weight status of children was categorised as either non-overweight (thinness and normal weight) (BMI Z-score for age < +1) or overweight including obesity (BMI Z-score for age ≥ +1·0).

Demographic and socio-economic data were collected through a questionnaire sent to parents/guardians. Maternal education was categorised as years of schooling into 0–8 years (primary school not completed to primary school completed), 9–11 years (secondary school not completed to secondary school completed) and ≥12 years (college degree not completed and higher) and was used as a proxy for family income.