Association of dietary fiber intake with general and abdominal obesity in children and adolescents: The Weight disorder survey of the CASPIAN-IV Study

Abstract

BACKGROUND: Dietary fiber intake might have a protective role against obesity. The aim of this study is to explore the association of dietary fiber intake with general and abdominal obesity in Iranian children and adolescents. MATERIAL AND METHODS: This cross-sectional nationwide study was conducted on 5187 students aged 6-18 years, living in 30 provinces of Iran. They were selected randomly through cluster sampling method. Data on demographic and anthropometric indices including weight, height and waist circumference (WC) were collected by trained interviewers. A valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ) was used to assess student's usual dietary intake including total dietary fiber. All dietary reports were converted to daily consumption (g/day) using household measures for different portion sizes. Food items were then converted to their nutrient content. Energy-adjusted dietary fiber intake (g/1000 kcal/day) was also calculated using the energy density method. Multivariate regression models were applied to explore the association between dietary fiber intake and anthropometric indices. RESULTS: The mean and standard deviation (SD) for age of participants were 11.40 (3.20) years. Of 5187 students, 52.6 were boys and 72.5 were from urban areas (participation rate: 79.7). White bread (32.5), white rice (17.1) and potato (11.7) were the most common sources of dietary fiber intake. Each 1 g/1000 Kcal increase in dietary fiber intake was significantly associated with lower weight and waist circumference (P = 0.006 and P = 0.008, respectively). CONCLUSION: Higher fiber intake was associated with lower anthropometric indices including weight and WC. Increased fiber intake should be encouraged for children and adolescents.