Abstract P193: Sex Moderates Diet Quality Differences in Integrated Collaborative Care for Comorbid Obesity and Depression: Post-Hoc Analysis of the Research Aimed at Improving Both Mood and Weight Randomized Clinical Trial

Abstract

Background: High-quality diets, such as the Dietary Approaches to Stop Hypertension (DASH), are associated with lower risk for obesity and obesity-related chronic diseases. It is unclear whether diet quality improves aside from reduced calories in evidence-based behavioral weight loss interventions. Objective: Leveraging data from the Research Aimed at Improving Both Mood and Weight (RAINBOW) randomized trial, the objective of this post hoc analysis is to investigate (1) whether the study intervention was associated with improved diet quality in adults with comorbid obesity and depression, compared to usual care; and (2) whether the associations were modified by sex. Methods: Participants completed 24-hour dietary recalls at baseline, 6, 12, 18, and 24 months. Dietary outcomes included the DASH score as the composite measure of diet quality and its components. Between-group differences in dietary outcomes were examined among 409 participants and by sex, using repeated-measures mixed-effects linear models. Results: Changes in DASH scores did not differ between the intervention and usual care control groups through 24 months in both women and men. Compared with controls, men in the intervention group had significantly decreased nut, seed, and legume intake at 6 (mean difference, -1.1; 95% CI, -1.9, -0.3 servings/day; P=0.01) and 12 months (-1.0; -2.0, -0.0 servings/day; P=0.048). Compared with controls, women in the intervention group had significantly decreased fruit and vegetable intake at 18 (-1.8; -2.9, -0.6 servings/day; P=0.002) and 24 months (-1.1; -2.2, -0.1 servings/day; P=0.03), and whole grain intake at 24 months (-0.5; -0.9, -0.1 servings/day; P=0.03), but increased percent calories from fat at 24 months (3.6; 0.6, 6.5; P=0.02). Conclusions: Diet quality not only did not improve in an effective behavioral weight loss intervention but deteriorated in women, in particular. These post-hoc findings warrant confirmation and may suggest that behavior change techniques targeting diet quality that are tailored to women and men need to be an explicit focus of behavioral weight loss interventions aside from caloric reductions.