Quantity and variety of food groups consumption and the risk of diabetes in adults: A prospective cohort study

Evidence remains inconsistent regarding the association between quantity of food groups and diabetes, and remains scarce regarding the relation of dietary diversity with diabetes.We aimed to evaluate the prospective relation of variety and quantity of 12 major food groups with new-onset diabetes.A total of 16,117 participants who were free of diabetes at baseline from China Health and Nutrition Survey were included. Dietary intake and variety score were measured by three consecutive 24-h dietary recalls combined with a household food inventory in each survey round. The study outcome was new-onset diabetes, defined as self-reported physician-diagnosed diabetes during the follow-up period. Cox proportional hazards models and restricted cubic spline analysis were used to estimate hazard ratios (HR) and dose-response relation, respectively.During a median follow-up duration of 9.0 years, a total of 1088 (6.7%) participants developed new-onset diabetes. Overall, there was a significant inverse association between dietary variety score and the risk of new-onset diabetes (per one point increment; HR, 0.85; 95% CI, 0.80-0.90). In addition, there were U-shaped associations of refined grains, whole grains, nuts, red meat, poultry, processed meat, dairy products, and aquatic products intake with diabetes, and L-shaped associations of legumes, vegetables, fruits, and eggs intake with diabetes (all P values for nonlinearity <0.001).Our results suggested that greater variety of food groups consumption was associated with significantly lower risk of new-onset diabetes. Furthermore, when the quantity of food groups intakes was relatively low, there was a negative correlation between the quantity of each different food group consumption and diabetes risk; however, when intake exceeded certain thresholds, the risks of new-onset diabetes increased or reached a plateau.