Feasibility of a Supervised Inpatient Low-Calorie Diet Program for Massive Weight Loss Prior to RYGB in Superobese Patients

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.

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.

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%.

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.