Abstract P211: Effect Of An Mobile Health Weight Loss Intervention On Healthy Eating Index Diet Quality: The Smarter Randomized Controlled Trial

Abstract

Introduction: Dietary modification is key to standard behavioral treatment for weight loss. However, few studies assess whether diet quality—the overall healthfulness of the diet—is improved over the course of the intervention. As diet quality is relevant to health separate from its effect on weight, it may be an important endpoint to assess. The purpose of this secondary analysis of a randomized mobile health weight loss trial was to assess whether self-monitoring with automated, personalized feedback (SM+FB) compared to self-monitoring alone (SM) resulted in improved diet quality. Methods: Adults (N=502) with overweight/obesity (n=251 in SM+FB; n=251 SM) were provided calorie, fat gram, and physical activity goals and instructed to weigh daily, wear a Fitbit activity tracker, and self-monitor diet. Feedback messages were sent up to three times daily to SM+FB participants and were based on participant reported intake of calories, fat, and sugar but did not specifically target diet quality. Diet data were collected from two dietary recalls at baseline, 6 months, and 12 months using the Automated Self-Administered system (ASA-24). The Simple Scoring method was used to calculate Healthy Eating Index 2015 (HEI-2015) total scores as it aligns with the Dietary Guidelines for Americans. Change in diet quality was assessed using two-way repeated measures analysis of variance. Missing dietary data was imputed using last observation carried forward. Analyses used intention to treat. Results: The overall sample was mostly female (79%), white (82.5%), and middle-aged (mean=45.0 years, SD=14.4 years). Baseline HEI-2015 total scores were similar between SM (mean=54.44, SE=0.78) and SM+FB (mean=55.49, SE=0.82) and did not improve for either group over 6 months (SM: mean=55.64, SE=0.77; SM+FB: mean=56.89, SE=0.88) or 12 months (SM: mean=56.21, SE=0.81; SM+FB: mean=56.10, SE=0.88). Group, time, and group by time interaction effects were all non-significant (p>0.003) after Bonferroni adjustment. Discussion: Given that the HEI-2015 total score ranges from 0 to 100 with 74 meeting Healthy People 2020 goals, the diet quality of participants was less than ideal (grade: F) at baseline. The small improvements over time were likely not clinically significant. Future mHealth interventions might consider ways to increase user engagement, customization of additional features beyond feedback, and the addition of more targeted nutritional education in order to improve diet quality.