The prevalence of obesity and overweight continues to increase worldwide, and Asian
populations are particularly vulnerable due to lower thresholds for metabolic risk
compared with Western populations. Individuals with overweight or mild-to-moderate
obesity (BMI 24.0-34.9 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 sutureless 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 15%
at 12 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 Asian adults with overweight
and mild-to-moderate obesity who have failed conservative weight reduction efforts.
Eligible participants will be randomized 1:1.5 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 3
months, 6 months, 12 months after enrollment.

The primary endpoint is percent TBWL at 12 months, assessed using standardized weight
measurement protocols. Secondary endpoints include %TBWL at 6 and 12 months, changes in
BMI, metabolic parameters (fasting plasma glucose, HbA1c, insulin resistance indices,
lipid profile), liver steatosis and fibrosis indices (e.g., controlled attenuation
parameter and liver stiffness by transient elastography), 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 Asian populations.