iWAIST Trial: ERCG (Endoscopic Radial Compression Gastroplasty) vs Optimized Lifestyle Intervention for Weight Loss

The prevalence of obesity and overweight continues to increase worldwide, and Chinese populations are particularly vulnerable due to lower thresholds for metabolic risk compared with Western populations. Individuals with overweight or mild-to-moderate obesity (BMI 24.0-37.4 kg/m²) often fail conservative measures but are ineligible or unwilling to undergo bariatric surgery because of its invasiveness, risk, and costs. This creates an unmet need for minimally invasive, effective, and scalable interventions. Endoscopic bariatric and metabolic therapies (EBMTs) have emerged as alternatives, but many existing procedures involve technically complex endoscopic suturing, high costs, or device-related risks. Investigators developed ERCG, a novel endoscopic procedure that reduces gastric volume by apposing the gastric walls using a newly designed clip-and-loop system. Preliminary studies demonstrated that ERCG can induce rapid weight loss, with mean percent total body weight loss (TBWL) of approximately 12% at 3 months, while maintaining a favorable safety profile. This randomized controlled trial aims to evaluate the efficacy and safety of ERCG compared with an optimized lifestyle intervention (OLI) in Chinese adults with overweight and mild-to-moderate obesity who have failed conservative weight reduction efforts. Eligible participants will be randomized 1:1 into two groups. The experimental group will undergo ERCG under general anesthesia or deep sedation, following a standardized perioperative protocol, then receive structured OLI. The control group will receive structured OLI consisting of individualized dietary counseling, caloric restriction, exercise prescription, and behavioral support. Follow-up visits are scheduled at 1 month, 2 month, 3 month and 6 month after enrollment. The primary endpoint is percent TBWL at 3 months, assessed using standardized weight measurement protocols. Secondary endpoints include %EBWL at 3 and 6 months, changes in BMI, metabolic parameters (fasting plasma glucose, HbA1c, insulin resistance indices, lipid profile), quality of life assessed by validated questionnaires (IWQOL-Lite), and the incidence of adverse events classified according to international standards. Randomization will be computer-generated with concealed allocation, and outcome assessors will be blinded to treatment assignment. Analyses will follow the intention-to-treat principle with appropriate methods for handling missing data. The study is expected to generate high-quality evidence regarding the short-term and medium-term efficacy of ERCG, to clarify its safety profile, and to determine whether ERCG can serve as a safe and scalable option bridging the therapeutic gap between conservative lifestyle approaches and bariatric surgery for overweight and mildly to moderately obese Chinese populations.