Dietary glycemic index and glycemic load in relation to risk of overweight in Japanese children and adolescents: the Ryukyus Child Health Study

Abstract

Epidemiologic evidence concerning the role of dietary glycemic index (GI) and glycemic load (GL) in obesity during childhood and adolescence is limited, particularly in non-Western populations. We examined the association between dietary GI and GL as well as dietary fiber intake and overweight status in Japanese children and adolescents. This Japanese cross-sectional study included 15,974 children (6-11 years; 7956 boys and 8018 girls) and 8202 adolescents (12-15 years; 3944 boys and 4258 girls). Dietary intake was assessed using a self-administered diet history questionnaire for children and adolescents. Body mass index (BMI) was calculated from self-reported body weight and height. Overweight was defined according to the International Obesity Task Force age- and sex-specific BMI cutoffs, which correspond to an adult BMI of 25 kg m(-2). The overall prevalence of overweight was 13.2%. Mean (s.d.) dietary GI was 63.0 (3.1), mean dietary GL was 85.0 (12.4) per 4184 kJ (1000 kcal) and mean dietary fiber intake was 5.9 (1.2) g/4184 kJ. After adjustment for potential confounding factors, dietary GL was positively associated with the risk of overweight in male children, female children and male adolescents (P for trend <0.0001, <0.0001 and 0.006, respectively), but not in female adolescents. No such independent associations were observed for dietary GI or fiber intake. This large cross-sectional study in Japan suggests that higher dietary GL is associated with increasing risk of overweight in male and female children and male adolescents, but not female adolescents.