Lifestyle changes in one behavioral domain may influence other health behaviors. A cluster-randomised controlled trial published in Diabetes, Obesity and Metabolism evaluated whether a nudge-based dietary intervention could produce spillover effects on physical activity and sleep among adults with type 2 diabetes.

The 2 × 2 factorial cluster-randomised trial was conducted in 12 primary healthcare centres in Beijing, China. Adults aged 18-59 years with type 2 diabetes were assigned to a 1-month nudge-based dietary intervention (n = 204) or a control group (n = 73). Physical activity was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and step-tracking mobile applications. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI).

At 3 months, daily step counts increased by 1,105 steps in the intervention group (p=0.02). This improvement was not sustained for 6 months or 24 months. Total physical activity and sleep quality showed modest but statistically nonsignificant short-term improvements. Mediation analysis showed that diabetes management self-efficacy at 3 months did not mediate the association between the dietary intervention and step counts.

The findings indicate that a nudge-based dietary intervention produced observable but short-lived spillover effects on daily physical activity among adults with type 2 diabetes.