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

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.

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).

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.

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.