Consumption of restaurant foods and incidence of type 2 diabetes in African American women

Background: Type 2 diabetes is a major problem in Western nations. Profound secular changes in the food environment and eating habits may play a role. In particular, consumption of foods prepared outside the home has greatly increased. Objective: We investigated the relation of restaurant meal consumption to incidence of type 2 diabetes among African American women with the use of data from the prospective Black Women's Health Study. Design: The participants have completed mailed follow-up questionnaires every 2 y since 1995, including food-frequency questionnaires that asked about the frequency of eating restaurant meals of various types. Cox proportional hazards models were used to calculate incidence rate ratios and 95% CIs for the association of type 2 diabetes incidence with various categories of consumption of each restaurant food relative to the lowest category, with adjustment for diabetes risk factors. Results: Among 44,072 participants aged 30-69 y and free of diabetes at baseline, 2873 incident cases of type 2 diabetes occurred during 10 y of follow-up. Consumption of restaurant meals of hamburgers, fried chicken, fried fish, and Chinese food were independently associated with an increased risk of type 2 diabetes. Incidence rate ratios for >= 2 such meals per week relative to none were 1.40 (95% CI: 1.14, 1.73) for hamburgers and 1.68 (95% CI: 1.36, 2.08) for fried chicken. Control for body mass index greatly reduced the estimates, which suggests that the associations are mediated through weight gain and obesity. Conclusion: The present study has identified a risk factor for type 2 diabetes that may be readily modifiable by dietary changes. Am J Clin Nutr 2010;91:465-71.