Obesity, Diet, Physical Activity and Sleep in Argentinian Adolescents Before and After the COVID‐19 Lockdown

AIMS: There have been numerous studies on the health effects of the COVID-19 lockdown, but long-term effects remain unknown. This study compares the pre- and postpandemic periods to assess changes in lifestyle habits affecting weight in adolescents. METHODS: We conducted a longitudinal prospective study on a cohort of 378 Argentinian adolescents assessed in 2019 and 2022. Anthropometric data included body mass index (Z_BMI) and waist-to-height ratio (WHtR). Lifestyle habits encompassed sleep, time to sleep, daily physical activity (DPA) and diet quality index (DQI). Changes in these outcomes were assessed by nonparametric two-way repeated measures analysis of variance (ANOVA) according to sex, BMI status at baseline and socioeconomic status (SES). RESULTS: The WHtR increased significantly from baseline to follow-up regardless of sex and SES, with no changes in BMI. The DQI increased with higher SES. From baseline to follow-up, there was a significant increase regardless of sex or SES. In contrast, changes in DPA were associated with BMI status at baseline, being significantly higher in overweight subjects at follow-up. Sleep shortening with increased interval between bedtime and falling asleep was consistent across all groups, with boys having the greatest increase in sleep time. CONCLUSIONS: The observed increase in abdominal obesity and worsening of sleep patterns could be consequences of a prolonged COVID-19 lockdown, whose deleterious effects on adolescent health require further research.