We evaluated whether dietary quality is a predictor of reduced diabetes risk and/or weight loss, independent of caloric intake in the diverse DPP cohort, a randomized clinical trial of adults at risk for diabetes. This secondary analysis included the 2920 participants (90.3% of randomized) with complete baseline and 1-year data (967 intensive lifestyle (ILS), 979 metformin, 974 placebo). Dietary intake was assessed using a 117-item food frequency questionnaire. Dietary quality was quantified using the Alternative Healthy Eating Index 2010 (AHEI), which ranges from 0 to 110 with higher scores corresponding to healthier diets. Participants were 50.8 ±10.6 years, 67.5% female, 44.7% minority race/ethnicity and baseline AHEI was 44.2 ±10.4. ILS participants had greater improvement (p<0.001) in AHEI over 1-year (4.2 ±9.0) compared to metformin (1.2 ±8.5) and placebo (1.4 ±8.4). We examined the association between AHEI change and weight change from baseline to 1 year using linear regression. One-year AHEI change and incident diabetes, based on fasting and 2h OGTT glucose, was evaluated using Cox proportional hazards models over an average 3 years follow-up. All models were evaluated within treatment group and adjusted for demographics, smoking, alcohol use, family history of diabetes, caloric intake, physical activity, BMI and AHEI, and change in caloric intake and physical activity. Models testing incident diabetes were further adjusted for baseline fasting and 2h glucose. AHEI change was associated with weight loss in ILS [β per unit increase (SE) -0.12 kg (0.03, p<0.001)], metformin [-0.09 kg (0.02, p<0.001)] and placebo [-0.05 kg (0.02, p=0.01)]. However, AHEI change did not predict incident diabetes in any group: hazard ratio per unit increase (95% CI) 1.00 (0.98-1.03) for ILS, 1.00 (0.98-1.02) in metformin and 1.00 (0.98-1.02) in placebo, before or after adjustment for weight change. Our results suggest that diet quality helps achieve weight loss, an important factor in diabetes prevention.
B. Allaire: None. A.H. Tjaden: None. J.W. Apolzan: None. D. Dabelea: None. L.M. Delahanty: Advisory Panel; Self; Jana Care Inc., Omada Health, Inc., Weight Watchers International, Inc. S. Edelstein: None. M.A. Hoskin: None. L.M. Jaacks: None. K.A. Temple: None. E.M. Venditti: None. J. Wylie-Rosett: None. DPP Research Group: None.
National Institute of Diabetes and Digestive and Kidney Diseases