Abstract P243: Greater Healthful Dietary Variety and Changes in Adiposity Indicators During a Weight-Loss Intervention: The POUNDS Lost Trial

Abstract

Background: Adhering to a healthy lower energy diet is essential for sustained weight loss. Greater variety within energy-poor, nutrient-dense foods may improve adherence by making the diet less monotonous, and therefore more enjoyable. Greater healthful dietary variety has been inversely associated with adiposity in cross-sectional studies, but it is unclear if it predicts longitudinal changes in body weight. Objective: To examine the longitudinal associations between initial changes in healthful dietary variety (0-6 months) and long-term changes in adiposity over 24-months in a weight-loss trial. Methods: Participants in the POUNDS Lost trial were advised to follow energy-restricted diets. Data for participants with complete dietary assessments at baseline and 6-months were analyzed (n=367). Healthful dietary variety was quantified using the validated US Healthy Food Diversity (US HFD) index, which measures the number of foods consumed and consistency of dietary selections and amounts with recommendations from the 2010 Dietary Guidelines for Americans. Changes in the US HFD index between baseline and 6-months were divided into tertiles (T); adults in T1 had reductions in the US HFD index, T2 maintained stable index values, and T3 had increased index values. Body weight and waist circumference (WC) were measured at 6, 12, 18, and 24-months and percent body fat and trunk fat were measured at 6 and 24-months using DEXA. Repeated measures ANOVA was used to test whether US HFD index change tertiles were significantly associated with adiposity over 24-months. Models were adjusted for age, sex, race, smoking, education, income, diet arm, changes in physical activity and energy intake, baseline adiposity indicator, and the interaction between the US HFD index change tertile and time. Results: Reductions in energy intake were equivalent across US HFD index change tertiles in multivariable models (-425 vs.-265 kcal in T1 vs.T3, p=0.08). An improved variety (T3) as compared to stable variety (T2) was associated with greater weight loss at 24-months (-4.75 vs. -2.63kg, p=0.03; linear p-trend=0.04) and greater decrease in total body fat in T3 vs. T2 (-1.10% vs. -0.006%, p=0.03; p-trend=0.04) and trunk fat (-1.29% vs. 0.08%, p=0.03; p-trend=0.04). An improved variety (T3) as compared to stable variety (T2) or reduced variety (T1) was associated with greater reduction in WC (-6.48cm (T3) vs. -3.98cm (T2), p=0.01; and -4.14cm (T1), p=0.04; linear p-trend=0.01). Reducing variety (T1) did not reduce or increase other adiposity indicators compared to stable or increased variety. Conclusions: Increasing healthful dietary variety while restricting energy intake may improve sustained reductions in adiposity among adults trying to lose weight.