Abstract
CONTEXT: The relationship between the variety and quantity of different sources of dietary-insoluble fiber intake and diabetes remain uncertain. OBJECTIVE: We aimed to investigate the associations between the variety and quantity of insoluble fiber intake from 6 major food sources and new-onset diabetes, using data from the China Health and Nutrition Survey (CHNS). METHODS: A total of 16 272 participants without diabetes at baseline from CHNS were included. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. Energy-adjusted dietary intake was used in analyses. The variety score of insoluble-fiber sources was defined as the number of specific-sourced insoluble fiber consumed at the appropriate level, accounting for both types and quantity of insoluble fiber. Participants with self-reported physician-diagnosed diabetes, or fasting glucose greater than or equal to 7.0 mmol/L or glycated hemoglobin A1c greater than or equal to 6.5% during follow-up were defined as having new-onset diabetes. RESULTS: During a median follow-up of 9.0 years, 1101 participants developed new-onset diabetes. There were U-shaped associations for energy-adjusted dietary intake of total insoluble fiber, and energy-adjusted insoluble fiber derived from refined and whole grains; and L-shaped associations for energy-adjusted insoluble fiber derived from vegetables, legumes, fruits, and tubers with new-onset diabetes (all P for nonlinearity < .001). Moreover, a higher variety score of insoluble fiber sources was significantly associated with a lower risk of new-onset diabetes (per 1-score increment, hazard ratio, 0.61; 95% CI, 0.58-0.65). CONCLUSION: There was an inverse association between the variety of insoluble fiber with appropriate quantity from different food sources and new-onset diabetes.