Effects of Intensive Lifestyle Interventions (ILI) on Weight Loss and Cardiometabolic Risks in Obese Adults With Metabolic Syndrome: A Randomized Clinical Trial

This study is a randomized, parallel-group, observer-masked clinical trial. A total of 200 obese participants with MetS will be enrolled. Eligible subjects will be randomly assigned to the ILI group or ULI group with an allocation ratio of 2:1. The ILI group will be instructed to eat in 8 hours while fasting in 16 hours on daily basis over 24 weeks. Furthermore, enhanced daily physical activities with walking more than 10,000 steps will be implemented. The enrolled participants will be instructed to follow a diet with reduction of daily intake of 500 kcals per day. ILI group will be asked to use the Health2Sync mobile app to track self-measured outcomes and daily diet control. The investigators objectively measure step counts for participants of ILI group during 24-week intervention period using a wearable device (Fitbit Inspire 2). Participants are asked to attach the pedometer on their waist belt, except while bathing and sleeping. The ULI group will be instructed to follow habitual meal timing. In addition, all participants of both groups will receive the health education. Anthropometric, sociodemographic data, biochemical variables, and metabolic variables will be measured at baseline and during follow-up visit. DEXA and MRI of abdomen will be measured at baseline and during following up visits. The proposed trial is designed to provide 85% statistical power to detect a significant difference in changes in the metabolic syndrome severity score after reduction > 5% body weight over 24 weeks.

After completion of the initial 24-week lifestyle intervention, which often has limited weight loss efficacy when used alone, a second-phase intervention will be conducted from week 26 to week 52. Participants in both the ILI and ULI groups will be randomly assigned in a 1:1 ratio to receive one of two evidence-based oral weight control medications: a GLP-1 receptor agonist (Rybelsus) or an SGLT-2 inhibitor (Forxiga), for a duration of 26 weeks. The ILI group will continue with the daily 8-hour time-restricted eating and 16-hour fasting regimen, along with walking more than 10,000 steps per day. This phase aims to evaluate the effects of these two medications on weight reduction and liver fat content, with or without prior 26-week intensive lifestyle intervention. After the 26-week medication intervention, all participants will be followed for an additional 52 weeks to assess the sustainability of weight loss.