Objective To evaluate the effects of meal replacement (Glucerna SR, Abbort) on weight loss and fat redistribution in patients with simple obesity. Methods Twenty-two simple obesity patients received dinner replacement with Glucerna for five weeks (6 spoons, about 52 g per time, 220.48 kcal [1 772 kJ]), once a day at night replacing dinner. The weight, blood pressure, BMI, lipid, total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), fasting plasma glucose, and insulin were all observed before and after dinner replacement. The fat distribution was detected by DEXA (dual energy X-ray absorptiometry). The study was done by before-after design in the same patients. Results The body weight (P<0.001) and BMI (P<0.001) were significantly decreased after dinner replacement in our group. Dinner replacement also led to significant decrease of total fat mass (P=0.035), fat mass percentage (P=0.033) and trunk fat mass (P=0.002), while the decreases of peripheral fat mass and arm fat/leg fat mass were not significant. Lipid profiles showed that TG was significantly decreased (P=0.028)and HDL was significantly increased (P<0.001) after dinner replacement. Dinner replacement with Glucerna also resulted in a reduced HOMA-IR, though without statistical significance (P=0.372). Conclusion Dinner replacement can greatly reduce the weight of obese patients, improving fat distribution and regulating blood lipid and glucose. Dinner replacement is tolerable and safe, and it can improve the metabolism of obese patients.