The study was conducted to describe body shapes of school age children using the degree of obesity index (DOI) and body mass index obesity index classified by the Ministry of Education, Science and Technology (M-BOI) and Seoul Metropolitan Office of Education (S-BOI).

In this cross sectional descriptive study health screening data for school children collected in 2007 was used.

Data were analyzed for 2,193 4th-6th grade boys (52%) and girls who attended 4 schools in rural areas. DOI determined that only 44.3% of students had average weight. This proportion was much lower than the results of other methods (74.3-77.6%). All three methods defined girls (51.3-61.8%) as skinnier than boys. Skinny and average body shaped children classified by DOI and obese children classified by S-BOI were heavier and taller and presented higher degrees of obesity (DO) and BMI scores than by other methods. M-BOI and S-BOI presented statistically significant positive correlations with weight, height, DO and BMI, while DOI was not correlated with height.

BMI based body shape classifications provide a more rigorous classification of body shape which are favorable for school health professionals with limited resources and policy makers for internationally comparable references.