Increasing obesity in school children in a transitional society and the effect of the weight control program.

Childhood obesity is an increasing problem in developed countries. Its persistence into adulthood with accompanied health risks has raised many concerns. In a country with rapid growing economy and changing life styles such as Thailand, the natural history of obesity in school children aged 6-12 years was investigated. Yearly weight and height measurements were performed from 1991 onwards. Of 1,156 primary school children enrolled in 1991, two year follow-up was possible in 1,106 cases. Prevalence of obesity, as diagnosed by weight-for-height > 120% of the Bangkok reference, rose from 12.2% in 1991 to 13.5% in 1992 and 15.6% in 1993. In two years, 74 non-obese children became obese while 28 obese children showed the opposite trend. For those obese children who attended the weight control program, their body mass indices and triceps skinfold thickness increased significantly less than those of the non-attendees in the first year. These findings persisted in the second year but were of a smaller magnitude. Results of this study demonstrate the trend of increasing obesity in school children in the transitional society and the short term benefit of a weight control program.