Patient-Delivered Continuous Care for Weight Loss Maintenance: A Randomized Clinical Trial.

Importance: Weight loss maintenance (WLM) is one of the most difficult challenges in obesity treatment. Continuous care, which involves frequent behavioral weight management sessions delivered by professional staff, shows promise; however, this care is costly and unsustainable. Thus, new, efficacious treatment models are needed for WLM.

Objective: To examine the efficacy of an entirely patient-delivered treatment for WLM compared with professionally delivered standard-of-care treatment (SOC).

Design, setting, and participants: This randomized clinical trial used a 2-phase WLM design. During phase 1, participants received an online weight loss program. Those who achieved 5% or greater weight loss in phase 1 were eligible for phase 2, the actual 18-month WLM trial. Participants in the maintenance trial were randomized to either an entirely patient-delivered lifestyle intervention for WLM or SOC delivered by professional staff. Participants aged 18 to 75 years with a body mass index (calculated as weight in kilograms divided by height in meters squared) of 25 to 50 were recruited from a single academic research center. Data were collected from February 2018 to March 2023, and data were analyzed from September 2024 to February 2025.

Interventions: Patient-to-patient treatment involved no professional staff; instead, mentors (successful weight losers) delivered intervention sessions and peers (fellow participants) provided ongoing, remotely delivered evidence-based social support. SOC was current best practice for WLM-group lifestyle intervention led by professionals. Both WLM interventions were 18 months in duration.

Main outcomes and measures: Primary outcome was weight change during the 18-month trial. Secondary outcomes included blood pressure, heart rate, physical activity, and sedentary behavior.

Results: Among the 287 randomized participants (240 [83.6%] female; mean [SD] age, 53.6 [0.9] years), 268 (93.4%) completed the trial. There was a statistically significant difference in weight change by arm; patient-to-patient treatment yielded significantly less weight regain than SOC (month 6: -1.44 kg [95% CI, -2.35 to 0.54] vs -0.16 [95% CI, -1.13 to 0.82]; month 12: 0.04 kg [95% CI, -0.86 to 0.95] vs 0.77 [95% CI, -0.21 to 1.47]; month 18: 0.77 kg [95% CI, -0.14 to 1.68] vs 2.37 [95% CI, 1.40 to 3.34]; P = .002). Parallel findings were observed for diastolic blood pressure, heart rate, physical activity, and sedentary behavior.

Conclusions and relevance: In this trial, patient-delivered lifestyle intervention (mentor interventionists plus peer support) yielded significantly better WLM and cardiovascular risk outcomes compared with SOC delivered by professionals. Future research may examine the effectiveness of this novel treatment approach in community and clinical settings.

Trial registration: ClinicalTrials.gov Identifier: NCT03396653.