Greater Healthful Dietary Variety Is Associated with Greater 2-Year Changes in Weight and Adiposity in the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) Trial

Abstract

Background: Greater healthful dietary variety has been inversely associated with body adiposity cross-sectionally; however, it remains unknown whether it can improve long-term weight loss.

Objective: This study prospectively examined associations between healthful dietary variety and short-term (6 mo) and long-term (2 y) changes in adiposity in the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) weight-loss trial completed in 2007.

Methods: Healthful dietary variety was assessed from 24-h recalls with the use of the US Healthy Food Diversity index among participants aged 30-70 y with overweight/obesity (n = 367). Changes in the index between baseline and 6 mo were divided into tertiles representing reduced (T1), stable (T2), or increased variety (T3). Body weight and waist circumference (WC) were measured every 6 mo, and the percentage of body fat and trunk fat were measured at 6 mo and 2 y. Associations between changes in variety and short-term and long-term changes in adiposity were analyzed by use of multivariable-adjusted generalized linear models and repeated-measures ANOVA.

Results: Regardless of dietary arm, T3 compared with T2 was associated with greater reduction in weight (-8.6 compared with -6.7 kg), WC (-9.1 compared with -6.1 cm), and body fat at 6 mo (β = -4.61 kg, P < 0.05). At 2 y, individuals in T3 compared with those in T2 or T1 maintained greater weight loss [-4.0 (T3) compared with -1.8 kg (T2 and T1), P = 0.02] and WC reduction [-5.4 (T3) compared with -3.0 (T2) and -2.9 cm (T1), P = 0.01]. Total body fat and trunk fat reductions were similarly greater in T3 than in T2.

Conclusions: Increasing healthful food variety in energy-restricted diets may improve sustained reductions in weight and adiposity among adults with overweight or obesity on weight-loss regimens. This trial is registered at clinicaltrials.gov as NCT00072995.

Keywords: POUNDS Lost; dietary variety/dietary diversity; healthy food diversity; obesity; weight loss; weight maintenance.

Conflict of interest statement

Author disclosures: M Vadiveloo, FM Sacks, CM Champagne, GA Bray, and J Mattei, no conflicts of interest.

© 2016 American Society for Nutrition.

Figures

FIGURE 1

Mean differences in body weight (A), waist circumference (B), percentage of body fat (C), and percentage of trunk fat (D) from baseline to 6 mo by tertiles of 6-mo changes in the US Healthy Food Diversity index among POUNDS Lost participants with overweight and obesity. Data are presented as adjusted means with standard errors. Mean changes are adjusted for age, sex, diet arm, smoking (current or ever smoker compared with nonsmoker), race/ethnicity (white compared with nonwhite), educational attainment (college graduate compared with some college or high school graduate), household income [low ($100,000)], change in physical activity score (0–6 mo), adherence to energy goals at 6 mo, and corresponding baseline adiposity indicator (i.e., body weight, waist circumference, total percentage of body fat, or total percentage of trunk fat). Changes in dietary variety were categorized into the following tertiles: T1 (−0.21 to −0.05), T2 (−0.04 to 0.01), and T3 (0.01–0.17). Tukey adjustment was used for all post-hoc comparisons between T1, T2, and T3. The value next to each bar represents the change in adiposity parameter for the corresponding tertile. Labeled means without a common letter differ. There are ∼119 participants in each tertile. POUNDS Lost, Preventing Overweight Using Novel Dietary Strategies; T1, reduced dietary variety; T2, stable dietary variety; T3, increased dietary variety.

FIGURE 2

Repeated-measures mean differences in body weight (A), waist circumference (B), percentage of body fat (C), and percentage of trunk fat (D) from baseline to 2 y by tertiles of 6-mo changes in the US Healthy Food Diversity index among POUNDS Lost participants with overweight and obesity. Data are presented as adjusted means with standard errors. Mean changes are adjusted for age, sex, diet arm, time, the interaction between the variety index and time, smoking (current or ever smoker compared with nonsmoker), race (white compared with nonwhite), educational attainment (college graduate compared with some college or high school graduate), household income [low ($100,000)], change in physical activity score (0–6 mo), adherence to energy goals at 6 mo, and baseline adiposity indicator (i.e., body weight, waist circumference, total percentage of body fat, or total percentage of trunk fat). Changes in dietary variety were categorized into the following tertiles: T1 (−0.21 to −0.05), T2 (−0.04 to 0.01), and T3 (0.01–0.17). Tukey adjustment was used for all post-hoc comparisons between T1, T2, and T3. The value next to each bar represents the change in adiposity parameter for the corresponding tertile. Labeled means without a common letter differ. There are ∼119 participants in each tertile. POUNDS Lost, Preventing Overweight Using Novel Dietary Strategies; T1, reduced dietary variety; T2, stable dietary variety; T3, increased dietary variety.