Prevalence and associated factors of overweight and obesity among primary school children: a cross-sectional study in Thanhhoa City, Vietnam

OBJECTIVE: To determine the prevalence and associated factors of overweight and obesity among primary school children (6–11 years old) in Thanhhoa city in 2021. DESIGN: Cross-sectional study. SETTING: Seven primary schools in Thanhhoa city, Vietnam. PARTICIPANTS: 782 children (and their parents). PRIMARY AND SECONDARY OUTCOME MEASURES: Two-stage cluster random sampling was used for selecting children and data were collected from January to February 2021. A self-administrated questionnaire was designed for children and their parents. Children’s height and weight were measured and body mass index (BMI)-for-age z-scores were computed using the WHO Anthro software V.1.0.4. Data were analysed using R software V.4.1.2. The associations between potential factors and childhood overweight/obesity were analysed through univariate and multivariate logistic regression analyses. Variables were selected using the Bayesian Model Averaging method. RESULTS: The prevalence of overweight/obesity among primary school children in Thanhhoa city was 35.93% (overweight 21.61% and obesity 14.32%). The proportion of overweight girls was nearly equal to that of boys (20.78% and 22.52%, respectively, p=0.6152) while the proportion of boys with obesity was four times as many as that of girls (23.86% and 5.62%, respectively, p<0.0001). Child’s sex was the factor significantly associated with childhood overweight/obesity. Boys had double the risk of being overweight/obese than girls (adjusted OR: aOR=2.48, p<0.0001). Other potential factors which may be associated with childhood overweight/obesity included mode of transport to school, the people living with the child, mother’s occupation, father’s education, eating confectionery, the total time of doing sports, and sedentary activities. CONCLUSION: One in every three primary school children in Thanhhoa city were either overweight or obese. Parents, teachers and policy-makers can implement interventions in the aforementioned factors to reduce the rate of childhood obesity. In forthcoming years, longitudinal studies should be conducted to determine the causal relationships between potential factors and childhood overweight/obesity.