Weight Loss and Engagement Among Active Users of a Dietitian-Led Digital Nutrition Platform: Retrospective Cohort Study.

BACKGROUND: Approximately 2.5 billion adults worldwide were living with overweight or obesity as of 2022, highlighting the need for comprehensive weight management solutions. Digital nutrition platforms have emerged as an accessible solution that can be implemented at scale. Nutrium Care is an employer-sponsored program delivered via the Nutrium platform, facilitating dietitian-led nutrition counseling through consultations and in-app communication, while also enabling users to track food intake, water consumption, and physical activity. OBJECTIVE: This study set out to characterize longitudinal weight changes among active users of the Nutrium Care program and estimate associations between program engagement and weight loss. METHODS: This retrospective cohort study analyzed deidentified data from adult users with overweight or obesity enrolled in the Nutrium Care program. Users were included if they were taking action to manage their weight and had at least 3 months of follow-up data available; these users were referred to as active users. The primary outcome was weight loss after 3 and 6 months, estimated using piecewise linear mixed-effects models. To estimate the association between engagement and weight loss, more- and less-engaged users were matched on sociodemographic characteristics. Engagement was defined by the number of dietitian appointments, days of active platform use, and logging of food, water intake, and physical exercise. RESULTS: The study included 10,288 active users, predominantly female (n=6887, 66.9%) and aged 18 to 49 years (n=9741, 94.7%), who contributed a median of 6 (IQR 4-9) months of data to the cohort. In the first 3 months, active users lost 2.0 kg (2.4% of baseline body weight; 95% CI 1.9-2.0 kg) on average, increasing to 2.3 kg (2.8%; 95% CI 2.2-2.4 kg) by 6 months. Higher program engagement was associated with more weight loss, with the strongest association estimated for at least 1 dietitian appointment every 2 months, corresponding to 0.8 kg (95% CI 0.7-1.0 kg) additional weight loss after 3 months. CONCLUSIONS: This retrospective cohort study addresses a critical research gap in hybrid nutrition interventions integrating professional dietitian support with an employer-sponsored digital nutrition program. Active users achieved weight loss, and regular contact with a dietitian was the strongest engagement factor associated with improved outcomes, supporting the potential role of professional support in digital weight management programs.