Under and over-nutrition in school-aged children and adolescents Ho Chi Minh City, Vietnam: a double burden rapidly shifting over a decade

Introduction: Survey data have indicated that Vietnam is experiencing rapid increases in childhood overweight and obesity, while under-nutrition co-exists. [1] Vietnamese adults and children have undergone a rapid change in diet and physical activity, particularly in large cities such as Ho Chi Minh City (HCMC). [2] Nutritional surveys conducted in HCMC indicated that the prevalence of overweight and obesity in children and adolescents increased from 2002 to 2009, while the prevalence of stunting and thinness appeared to decrease, although it remained a significant issue.[3] More recent evidence has been lacking. Methods: We estimated prevalence of under and over-nutrition in a cross-sectional survey of 10,949 schoolaged children and adolescents (6 – 18 years old) in HCMC, Vietnam and compared with the previous surveys in 2002/2004 and 2009. A representative sample of children was selected from 30 schools (primary, secondary and high schools) in the school year 2014-2015. Summary prevalence estimates of nutritional status indicators were weighted based on the population of students in each stratum (urban or rural) at each school level, and the proportion of surveyed students in each school. Results: The prevalence of over-nutrition in school year 2014-2015 was very high, with 50 – 60% of primary school children overweight or obese. Compared with previous surveys, the prevalence of overweight and obesity was two to four times higher, whereas the prevalence estimates for stunting and thinness were two to three times lower compared to the 2002/04 estimates. Thus the prevalence of overweight and obesity has been doubled every 5 year, while undernutrition among school-aged children and adolescents still coexists with the prevalence varying from 2% to approximately 20%. Over-nutrition was particularly common among primary school children (20-30% were overweight; a further 20-30% were obese). Abdominal obesity was also prevalent, with 30-50% of school children affected. There was also substantial coexistence of under-nutrition, particularly in high school students. Across all age groups, boys were significantly more likely to be obese than girls. Overnutrition was more prevalent in urban areas; under-nutrition was more common in rural areas. The double burden of malnutrition also existed within individuals. There was a high prevalence of overweight/obesity in stunted adolescents, with around one in four being overweight or obese, reflecting the double burden of malnutrition at the individual level. Full details of prevalence estimates and changes over time will be presented. Conclusion: Overall, this study demonstrates a very high prevalence of over-nutrition, particularly in primary school children, and the coexistence of under-nutrition in high school children in HCMC, Vietnam. While our findings suggest that stunting prevalence is decreasing, these data also indicate that it remains necessary to consider under-nutrition among those in high school to mitigate the risk of chronic disease development among children of the next generation. The substantial increase in overweight and obesity over the examined 12 year period suggests that HCMC children are moving quickly through the nutrition transition. Urgent comprehensive efforts are required from multiple sectors including governments, industry, and community-level organizations to address the double burden of malnutrition in Vietnam. (author)