The prevalence of obesity is increasing rapidly worldwide, increasing the risk of several common chronic diseases. To ascertain which of the three diet scores - Alternative Healthy Eating Index 2010 (AHEI), Dietary Inflammatory Index (DII) and Mediterranean Diet Score (MDS) was a better predictor of future obesity, assessed as body mass index (BMI) or waist to hip circumference ratio (WHR), in the Melbourne Collaborative Cohort Study (MCCS).Prospective cohort study in 27,834 men and women aged between 40 and 69 years at baseline (1990-94). Body size measures were taken at baseline and follow-up in 2003-7. Diet was measure at baseline using a 121-item food frequency questionnaire, along with confounders - age, sex, measure of socioeconomic status, smoking status, alcohol drinking status, physical activity level, country of birth, baseline body size measure (BMI or WHR as applicable). Regression coefficients and 95% confidence intervals for the association of dietary scores at baseline with BMI and WHR at follow-up 2 were generated separately using multivariate linear regression models adjusting for variables listed above and dietary energy intake. Both BMI and WHR at follow-up increased across quintiles of baseline DII (Q5 vs. Q1 BMI 0.4102 (0.2060, 0.6145); WHR 0.0094 (0.0061, 0.0128)), while for AHEI the association was inverse (Q5 vs. Q1 BMI -0.5139 (-0.6791, -0.3487); WHR -0.0107 (-0.0134, -0.0080). Only WHR at follow-up was inversely associated with categories of baseline MDS (G3 vs. G1 BMI -0.0540 (-0.2349, 0.1270); WHR -0.0040 (-0.0070, -0.0010)). Based on Akaike’s Information Criterion (AIC) and Bayesian Information Criterion (BIC) statistics, AHEI was a stronger predictor of increased body size at follow-up than the other diet scores. Poor quality/pro-inflammatory diets predicted future overall and abdominal obesity. The AHEI may provide the best way to operationalise this and capture subtle differences between the scores.
B. de Courten: None. M. Karim: None. A. Hodge: None.