Automated Behavioral Workplace Intervention to Prevent Weight Gain and Improve Diet: The ChooseWell 365 Randomized Clinical Trial

IMPORTANCE: Personalized interventions that leverage workplace data and environments could improve effectiveness, sustainability, and scalability of employee wellness programs. OBJECTIVE: To test an automated behavioral intervention to prevent weight gain and improve diet using employee cafeteria purchasing data. DESIGN, SETTING, AND PARTICIPANTS: This individual-level randomized clinical trial of a 12-month intervention with 12 months of follow-up was conducted among employees of a hospital in Boston, Massachusetts, who purchased food at on-site cafeterias that used traffic-light labels (ie, green indicates healthy; yellow, less healthy; red, unhealthy). Participants were enrolled September 2016 to February 2018. Data were analyzed from May to September 2020. INTERVENTIONS: For 12 months, participants in the intervention group received 2 emails per week with feedback on previous cafeteria purchases and personalized health and lifestyle tips and 1 letter per month with peer comparisons and financial incentives for healthier purchases. Emails and letters were automatically generated using survey, health, and cafeteria data. Control group participants received 1 letter per month with general healthy lifestyle information. MAIN OUTCOMES AND MEASURES: The main outcome was change in weight from baseline to 12 months and 24 months of follow-up. Secondary outcomes included changes in cafeteria purchases, including proportion of green- and red-labeled purchases and calories purchased per day, from baseline (12 months preintervention) to the intervention (months 1-12) and follow-up (months 13-24) periods. Baseline Healthy Eating Index-15 (HEI-15) scores were compared to HEI-15 scores at 6, 12, and 24 months. RESULTS: Among 602 employees enrolled (mean [SD] age, 43.6 [12.2] years; 478 [79.4%] women), 299 were randomized to the intervention group and 303 were randomized to the control group. Baseline mean (SD) body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was 28.3 (6.6) and HEI-15 score was 60.4 (12.4). There were no between-group differences in weight change at 12 (0.2 [95% CI, −0.6 to 1.0] kg) or 24 (0.6 [95% CI, −0.3 to 1.4] kg) months. Compared with baseline, the intervention group increased green-labeled purchases by 7.3% (95% CI, 5.4% to 9.3%) and decreased red-labeled purchases by 3.9% (95% CI, −5.0% to −2.7%) and calories purchased per day by 49.5 (95% CI, −75.2 to −23.9) kcal more than the control group during the intervention period. In the intervention group, differences in changes in green (4.8% [95% CI, 2.9% to 6.8%]) and red purchases (−3.1% [95% CI, −4.3% to −2.0%]) were sustained at the 24-month follow-up. Differences in changes in HEI-15 scores were not significantly different in the intervention compared with the control group at 6 (2.2 [95% CI, 0 to 4.4]), 12 (1.8 [95% CI, −0.6 to 4.1]), and 24 (1.6, 95% CI, −0.7 to 3.8]) months. CONCLUSIONS AND RELEVANCE: The findings of this randomized clinical trial suggest that an automated behavioral intervention using workplace cafeteria data improved employees’ food choices but did not prevent weight gain over 2 years. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02660086