Feasibility of a supervised inpatient low-calorie diet program for massive weight loss prior to RYGB in superobese patients

Background: This study was undertaken to determine the feasibility of an inpatient low-calorie program for a substantial decrease of preoperative weight (>10 points in BMI) in superobese patients. Methods: Five patients were hospitalized for an average of 11 weeks and were placed on a low-calorie liquid diet (<900 kcal/day) and an exercise program. Following a drop of ten points in BMI, they underwent a Roux-en-Y gastric bypass (RYGB). Hemoglobin A1c and lipid profiles were obtained at the beginning of the diet, prior to surgery and at the last follow-up appointment. Our results were compared to the National Surgical Quality Improvement Program (NSQIP) database, which included 1,046 bariatric operations performed at VA centers between October 1999 and August 2007. Results: All five patients were massively obese men (body mass index (BMI)=64.3±2.1 kg/m²; 54.7±2.6 years old; four of five were white) with multiple comorbid conditions, which placed them in a substantially higher risk for bariatric surgery. Of the four diabetic patients, two were insulin dependent. There was an average decrease in BMI by 12.7 points (85.8±6.0 lb) during the preoperative diet period (11 weeks). All patients underwent RYGB without complications. This cohort of patients further decreased their BMI by 10.6 points (88.4± 29.4 lb) following surgical intervention. The total combined preoperative and postoperative excess body weight loss was 89% (10.6-month average follow-up). Sleep apnea resolved following gastric bypass but did not improve during the preoperative weight loss period. Hypertension, osteoarthritis, and dyslipidemia all improved following surgical intervention. Hemoglobin A1c decreased by 1.9% during diet-induced weight loss with no further improvement being noted after surgery. The two insulin-dependent diabetic patients discontinued insulin therapy following surgery. The NSQIP database contained 77 patients with similar characteristics to our cohort of patients. The 30-day mortality for this cohort of patients was 3.9% with a complication rate of 33.8%. Conclusions: Massive preoperative weight loss is possible to achieve with a liquid protein diet in superobese patients greatly facilitating gastric bypass surgery in an otherwise high-risk patient population.