OBJECTIVES: Weight loss is a crucial in controlling type 2 diabetes mellitus. We assessed the effectiveness of financial and social incentives using behavioral economics to reduce body weight in patients with newly diagnosed type 2 diabetes.

METHODS: We conducted a pragmatic randomized clinical trial with a 6-month intervention period from June 2021 to December 2023. Adults with newly diagnosed type 2 diabetes recruited at public primary care clinics. Participants were randomly assigned to three groups to incentive increased physical activity: financial incentive, financial and social incentive, and control. Participants in the incentive groups received personalized weekly step targets along with loss-framed financial incentives starting at $128 USD (HKD 1000). Participants lost $5 USD each week if their step target was not met. For the social incentive, participant weekly step performance was shared with their nominated supporters to provide peer encouragement. Intent-to-treat analysis using weighted generalized estimating equations (WGEE) was performed to assess changes in body weight. ClinicalTrials.gov identifier: NCT04917926

RESULTS: Among 104 adults newly diagnosed with type 2 diabetes, the mean age was 55.0 (53.9% female). Median baseline weight for the control group was 66.2kg (IQR: 16.85kg; BMI: 25.8), the financial incentive group was 72.0 kg (IQR: 25.0kg; BMI: 26.3), and the combined financial and social incentive group was 66.1kg (IQR: 17.9kg; BMI: 25.7). Compared to the control group, significant weight loss occurred at 6-months in the social incentive group (-2.41 kg, p=0.015). Participants from the financial incentive group showed a non-significant decrease in weight (-0.46 kg).Participants in both incentive groups had non-significant increases in daily step counts (financial incentive: 907, financial and social incentive: 1752). Mean payout for financial incentives was USD 100.67 and financial and social incentives was USD 113.38.

CONCLUSIONS: Financial incentives with peer support can achieve weight loss in patients newly diagnosed with type 2 diabetes.