Overweight and obesity is a public health problem in preschool children and apparently becoming widespread in urban areas of HCMC. Overweight and obesity in children were strongly associated with parental overweight status, but longer duration of breast-feeding and longer sleep duration at night appear to protect against overweight and obesity in young children.

ObjectiveTo assess the trends in overweight and obesity in pre-school children in urban areas of Ho Chi Minh City (HCMC), Vietnam, over the period 2002 to 2005.DesignTwo cross-sectional studies were conducted in 2002 and 2005. Multistage cluster sampling was used in both surveys to select the subjects. Sociodemographic information was collected using a self-administered questionnaire given to parents in 2002 and using an interview-administered questionnaire to parents in 2005. Weight and height were measured using the same standard methods in both surveys. BMI (kg/m2) was calculated and overweight/obesity was defined using the age- and sex-specific BMI cut-off points proposed by the International Obesity Taskforce.Subjects and settingChildren aged 4 to 5 years, attending pre-schools in urban areas of HCMC, Vietnam, in 2002 (n492) and 2005 (n670).ResultsThe prevalence of overweight and obesity almost doubled from 2002 to 2005 (21·4 % and 36·8 %, respectively). The increase was more evident in less wealthy districts than in wealthy districts. The proportion of boys classified as obese in 2005 (22·5 %) was three times that in 2002 (6·9 %).ConclusionThe prevalence of overweight and obesity has increased rapidly in children aged 4 to 5 years in urban areas, and especially in less wealthy districts, over a 3-year period. These results signal an urgent need for prevention programmes to control and reverse this rapid upward trend in overweight and obesity in young children in HCMC.