This study was conducted to investigate the body weight control, attitudes, lifestyles and dietary habits according to the obesity index of elementary school students. This study utilized questionnaires and body composition measurements collected with a bio- electrical impedance analyzer(Inbody 4.0). Specifically, differences between the underweight group, normal group, and overweight group were tested by a $x^2$-test or ANOVA and Duncan's multiple range test. The subjects consisted of 571 elementary school students residing in Chonbuk Province. The average age, height, weight, and BMI of the male subjects was 11.5 years, 150.0 cm, 45.2 kg and $20.0\;kg/m^2$, respectively. The average age, height, weight, and BMI of the female subjects was 11.5 years, 152.2 cm, 46.1 kg and $19.8\;kg/m^2$, respectively. Twenty percent of the subjects were in the underweight group, 52.2% were in the normal weight group, and 27.8% were in the overweight group according to the Korean Pediatrics Society standards. A total of 50.2% of the subjects were dissatisfied with their body weight, while 36.8% of underweight, 42.3% of normal weight, and 81.1% of overweight subjects were dissatisfied with their weight. Fifty two percent of the subjects had attempted to reduce their body weight, including 50% of the normal weight group. The main reason for wanting to reduce body weight was to maintain health. The percentage of subjects who had received body weight control education was 41.3%, but 77.6% of the subjects thought it was necessary. Poor time management, lack of physical activity, portion size of meals, unbalanced diet, frequent consumption of convenience foods, and frequent snacking all affected the obesity index. Overall, the results of this study indicate that it is necessary to develop weight control programs for all elementary school students who are underweight, normal weight, and overweight.