School performance and weight status of children and young adolescents in a transitional society in Thailand.

Abstract

To study the association between current or previous weight status and school performance among children and young adolescents of Hat Yai municipality, southern Thailand. Cross-sectional and longitudinal study. Primary and secondary schools of Hat Yai municipality, southern Thailand. 1207 grades 3-6 and 587 grades 7-9 students. Body mass index (BMI, kg/m2) calculated from weight and height measurement of subjects in 1992 and 1994; parental education level and occupation, and monthly income, by questionnaire performed in 1992; grade-point-average (GPA) and grades of mathematics and Thai language from the school records of final examinations in 1994. Overweight subjects (BMI value > 85th percentile of the NHANES-I data for age and gender) in grades 7-9 had a mean GPA 0.20 point (95% confidence internal (CI) = 0.04, 0.37) lower than that of the normal weight children after controlling for gender, age, school and grade. They were twice more likely to have low grades (lower than 2 on the scales of 0-4) of mathematics and Thai language than normal weight children. There were no associations between GPA or individual subject grades and previous BMI status in 1992. Children in grades 7-9 who became overweight over the two years, had a mean GPA of 0.48 point lower than those who did not become overweight (95% CI = 0.12, 0.84). In grades 3-6 subjects, however, becoming overweight had no effect on GPA and individual subject scores. Our study showed that being overweight and becoming overweight during adolescence (grades 7-9) was associated with poor school performance, whereas such an association did not exist in children (grades 3-6).