Background <p>Metabolic bariatric surgery is the most effective treatment for achieving sustainable weight loss in patients with severe obesity. However, changes in body composition, particularly limb composition, after sleeve gastrectomy (SG) in the Asian population have not been widely reported. Additionally, few studies have focused on predicting short-term weight loss following SG.</p> Methods <p>We evaluated 159 patients with obesity who underwent SG between May 2020 and June 2023 at our hospital. Each patient's demographic, anthropometric, laboratory, and body composition data were collected at baseline and at 1, 3, 6, and 12&#xa0;months post-surgery. Logistic regression analysis was used to identify independent predictors of weight loss.</p> Results <p>The mean age of the 159 patients was 30.4 ± 7.7&#xa0;years, with 78.0% being female. Compared to baseline values, anthropometric parameters and metabolic profiles improved significantly after surgery. All body composition indices decreased, with fat mass (FM, in kg and percentage), visceral fat area (VFA), and obesity degree continuing to decline up to 1&#xa0;year postoperatively. The percentage of excess weight loss (EWL%) reached 55.7 ± 17.6% at 3&#xa0;months, meeting the standard for effective weight loss. Eleven factors were negatively correlated with EWL%, and obesity degree was identified as an independent predictor of weight loss (OR: 0.951, P = 0.001). The area under the receiver operating characteristic curve for obesity degree was 0.781 (95% CI: 0.668–0.894, P &lt; 0.001), with sensitivity and specificity values of 0.643 and 0.857, respectively, and a cutoff value of 193.5%.</p> Conclusions <p>Sleeve gastrectomy significantly improved anthropometric and metabolic variables, achieving effective short-term weight loss. Body composition changes were observed across the whole body, limbs, and trunk. Obesity degree was closely associated with effective weight loss after surgery and may serve as a potentially useful metric for clinical practice.</p>