Dietary fiber intake, dietary glycemic index and load, and body mass index: a cross-sectional study of 3931 Japanese women aged 18–20 years

Abstract

Few observational studies have investigated dietary fiber intake and dietary glycemic index (GI) and glycemic load (GL) simultaneously in relation to obesity, particularly in non-Western populations. We examined the associations between dietary fiber intake and dietary GI and GL, and body mass index (BMI) in young Japanese women. Cross-sectional study. A total of 3931 female Japanese dietetic students aged 18-20 years from 53 institutions in Japan. Dietary fiber intake and dietary GI and GL (GI for glucose=100) were assessed by a validated, self-administered, diet history questionnaire. BMI was calculated from self-reported body weight and height. Mean values of BMI, dietary fiber intake, dietary GI and dietary GL were 21.0 kg/m(2), 6.5 g/4186 kJ, 65.1 and 82.1/4186 kJ, respectively. White rice (GI=77) was the major contributor to dietary GI and GL (45.8%). After controlling for potential dietary and nondietary confounding factors, dietary fiber intake was negatively correlated with BMI (adjusted mean=21.1 kg/m(2) in the lowest and 20.7 kg/m(2) in the highest quintiles; P for trend=0.0007). Conversely, dietary GI and GL were independently positively correlated with BMI (20.8 and 21.2 kg/m(2); P for trend=0.03, and 20.5 and 21.5 kg/m(2); P for trend=0.0005, respectively). Dietary fiber intake showed an independent negative association with BMI, and dietary GI and GL showed an independent positive association with BMI among relatively lean young Japanese women.