Comparison of the impact of intensified lifestyle and glucagon-like peptide-1 receptor agonist (GLP-1RA) combined with lifestyle intervention on body composition in adult patients with overweight or obesity.The clinical data of 197 overweight or obese patients who were treated at the Zhongshan Hospital, Fudan University from February 2022 to June 2024 were retrospectively analyzed, including 75 males and 122 females, aged (36.7±10.9) years. Patients were divided into an intensified lifestyle intervention group (=84) and a GLP-1RA combined with lifestyle therapy group (=113) based on the intervention approach. Collected clinical data of patients. After adjusting for gender, age, and baseline BMI using generalized linear models, analyze the association between the changes in various indicators [including body weight, body mass index (BMI), body fat percentage, fat mass (FM), fat mass index (FMI), fat-free mass (FFM), and fat-free mass index (FFMI)] and the intervention methods.Body weight, BMI, waist circumference, diastolic blood pressure, FM, FFM, FMI, FFMI, fasting blood glucose, insulin resistance index, alanine aminotransferase, and controlled attenuation parameter were lower in the intensive lifestyle intervention group compared to the GLP-1RA combined with lifestyle intervention group (all0.05). There was no statistically significant difference between the two groups in terms of age, gender, systolic blood pressure, body fat percentage, total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, aspartate aminotransferase, and elasticity values (all0.05). After 12 weeks of intervention, the results of the generalized linear model showed that the reduction magnitudes of body weight, FFM, and FFMI were associated with the intervention methods (all0.05). The GLP-1RA combined with lifestyle intervention group showed greater reductions in body weight [(7.8±4.3) vs (5.1±4.5) kg], FFM [(2.2±2.1) vs (1.0±1.9) kg], and FFMI [(0.7±0.5) vs (0.3±0.5) kg/m] compared to the intensive lifestyle intervention group (all0.05). After 24 weeks of intervention, both groups exhibited decreases in post-weight-loss body weight, BMI, body fat percentage, FM, FFM, FMI, and FFMI compared to pre-weight-loss values (all0.001). The results of the generalized linear model indicated that the reduction magnitudes of body fat percentage, FM, FFM, FMI, and FFMI were associated with the intervention methods (all0.05). The intensive lifestyle intervention group showed greater reductions in body fat percentage (5.8%±3.0% vs 3.9%±4.2%), FM[(8.9±4.1) vs (7.0±5.7) kg], and FMI [(3.1±1.4) vs (2.4±1.9) kg/m] compared to the GLP-1RA combined with lifestyle intervention group, while the reductions in FFM [(1.5±2.5) vs (2.8±3.4) kg] and FFMI [(0.5±0.9) vs (0.9±1.2) kg/m] were smaller (all0.05).In weight loss treatment, the intensive lifestyle retains more lean body mass than the GLP-1RA combined lifestyle. Objective: Methods: Results: Conclusion: n n P P P P P P P2 2 2