Introduction
Vietnam has a nutrition transition leading to a rapid increase in the prevalence of
overweight and obesity among adolescents whose lifestyles become more and more
sedentary with lower levels of physical activity. Overweight and obesity among
adolescents is growing with time in urban areas of Vietnam. Obesity in adolescence
substantially increases the risk of cardiovascular diseases and their associated health
deficiencies in adulthood. Additionally, obesity in adulthood is a high risk factor for
chronic diseases.
Objectives
Our study aimed at assessing the physical activities, the sedentary behaviors, and the
dietary intake with regard to the prevalence of overweight and obesity among junior high
school students (11-14 years) in urban areas of Ho Chi Minh City, Vietnam.
Methods
A representative sample of 1,989 students aged 11-14 years was selected using a
multistage cluster sampling method. 23 schools were randomly selected from the full list
of all public junior high schools. In each selected school, 2 classes were chosen at random
and all students from each selected class were examined. Age- and sex-adjusted
overweight and obesity were defined using International Obesity Taskforce cut-offs.
Physical activity, sedentary behaviors, and dietary intake were collected based on
validated questionnaires for Vietnamese adolescents. Multiple logistic regressions were
used to assess the predictive value of risk factors on prevalence of overweight or obesity.
Results
The prevalences of overweight and obesity were 17.8% and 3.2%, respectively. From
2004 to 2010, the prevalence of overweight and obesity significantly increased from
11.7% and 2% to 17.8% and 3.2%, respectively (p = 0.001). The annual rate of change in
obesity prevalence was +1.02% per year. 53.8% spent more than 2 h/day in small-screen
recreations (boys/girls=63%/46%, 95%CI:[1.26-1.48], p = 0.001). Adolescents spent 1.5
h/day (median) in physical activity, with higher values for boys than girls (p = 0.001), and
33.9% were categorized as inactive. Total energy intake exceeded the Vietnam
Recommended Dietary Allowances 2007. Using multiple logistic regression, high use of
small-screen recreations at younger age was predictive of overweight and obesity
(OR=1.59, 95%CI:[1.06-2.38], p = 0.02). Younger boys and inactivity were significantly
associated with overweight or obesity prevalence. In girls, an inverse association was
observed between dietary intake and overweight or obesity.
Conclusions
In urban areas of Ho Chi Minh City, prevalence of overweight and obesity is still
increasing among adolescents who have sedentary behaviors, few physical activities, and a
total energy intake exceeding the Vietnam Recommended Dietary Allowances 2007.
Public health programs should therefore be improved in order to promote good eating
habits and physical activity among youths in Ho Chi Minh City.