RESUMEN
OBJECTIVE: Behavioral obesity treatment implemented in primary care is efficacious but typically involves face-to-face or phone contact. This study evaluated enrollment, engagement, and 12-week weight loss in a fully automated online behavioral weight-loss intervention implemented pragmatically in a primary care network. METHODS: As part of routine primary care, providers and nurse care managers offered a no-cost online obesity treatment program to 1,721 patients. Of these, 721 consented and were eligible (aged 18-75 years with BMI ≥ 25 kg/m2 and internet access), and 464 started the program. The program included 12 weekly online lessons, a self-monitoring platform, and automated feedback. RESULTS: More than one-quarter of patients who were offered the program (26%) initiated treatment. In intent-to-treat analyses using all data available, mean 12-week weight change was -5.10% (SE = 0.21). Patients who submitted their weights on all 12 weeks (37% of 464) lost an estimated 7.2% body weight versus 3.4% in those submitting less frequently. CONCLUSIONS: This fully automated online program, implemented into the routine workflow of a primary care setting without any human counseling or researcher involvement, produced clinically meaningful short-term weight loss. Greater program engagement was associated with greater weight loss; efforts are needed to understand barriers to engagement.