OBJECTIVE To explore the value of nutrition management in obese patients with type 2 diabetes mellitus(T2DM) after laparoscopic sleeve gastrectomy(LSG). METHODS Clinical data of 22 obese T2DM patients undergoing LSG from March 2013 to July 2015 in Fudan University Pudong Medical Center were collected. All the patients strictly followed the specialized instruction by nutritionists: diabetic and low calorie diet 3347.2 to 5020.8 kJ (800 to 1200 kcal) per day before the operation; low calorie liquid diet 2510.4 kJ(600 kcal) per day before operation for promoting gastric emptying; fasting diet before postoperative ventilation; clear liquid diet 1673.6 to 2510.4 kJ (400 to 600 kcal) per day after postoperative ventilation (liquid intake >2000 ml); low fat liquid diet 2928.8 to 3765.6 kJ (700 to 900 kcal) per day (protein 60 g per day at least, 2000 ml liquid) 2 weeks after the operation; semi-liquid diet 1 month after operation and gradually normal diet. All the 22 patients were followed up at 1 week, 1, 3, 6 months after operation on time. Changes of body weight, waist circumference, hip circumference, body mass index(BMI), blood glucose indexes induding fasting blood glucose(FBG), 2-hour postparandial blood glucose(PBG), fasting C-peptide, 2-hour postprandial C-peptide, fasting serum inculin(FINS), 2-hour postprandial inculin(INS), HbAlc, blood pressure and blood lipid indexes were observed and analyzed before and 1 week, 1, 3, 6 months after operation. RESULTS The average age of 22 patients (10 men and 12 women) was 38.6 years (18 to 66 years). The duration of diabetes varied from 1 month to 15 years. Comorbidity included 12 patients of high blood pressure, 14 of fatty liver, 1 of coronary heart disease, 1 of gout, 1 of chronic thyroiditis and 1 of menstrual disorder. LSG was performed successfully in all the patients and no severe complications and transference to laparotomy occurred. As compared to pre-operation, at 6 months after operation, the average body weight decreased from (103.9±20.2) kg to (80.9±12.6) kg (t=6.294, P=0.000), waist circumference from (118.6±13.8) cm to (96.4±8.0) cm (t=6.331, P=0.000), hip circumference from (116.9±12.6) cm to (104.0±7.7) cm (t=3.854, P=0.000), BMI from (36.2±5.9) kg/m2 to (27.9±3.5) kg/m2 (t=5.630, P=0.000), showing a decreasing trend over time. There was no underweight patient after 6 months follow-up. As compared to pre-operation, at 6 months after operation, the average FBG reduced from (7.4±1.4) mmol/L to (6.0±0.9) mmol/L (t=3.172, P=0.003), 2 h PBG from (14.1±4.9) mmol/L to (7.5±2.2) mmol/L (t=7.026, P=0.000), FINS from (160.0±71.9) mIU/L to (43.8±20.8) mIU/L (t=7.259, P=0.000), 2-hour postprandial INS from (437.6±261.4) mIU/L to (140.5±104.6) mIU/L (t=5.858, P=0.000), fasting C-peptide from (1.1±0.6) μg/L to (0.7±0.3) μg/L (t=3.560, P=0.000), 2-hour postprandial C-peptide from (2.5±0.9) μg/L to (1.5±0.7) μg/L (t=3.865, P=0.000), HbAlc from (8.0±1.6)% to (5.9±0.6)% (t=5.953, P=0.000), showing a decreasing trend over time except FBG, 2h postprandial C-peptide and HbAlc(all P<0.05). FBG and 2-hour PBG of 16 patients returned to normal 3 months after the operation. Blood pressure and trigly ceride decreased obviously 6 months after operation compared to pre-operation with significant difference(P<0.05). At 6 months after operation, blood pressure of 8 comorbidity patients with high blood pressure became normal (8/12, 66.7%) and of 4 patients improved(4/12, 33.3%); B ultrasound examination revealed normal in 11 comorbidity patients with fatty liver(11/14,78.6%) and improvement in 3 patients (3/14,15.4%). Blood uric acid of the gout patient and the menstruation of the menstrual disorder patient returned to normal 3 months and 1 month after the operation respectively. CONCLUSIONS As for obese patients with T2DM undergoing LSG, reasonable nutrition management is helpful to decrease body weight, and to obtain an ideal improvement of blood glucose and blood lipid levels.