Effectiveness, Compliance, and Acceptability of Preoperative Weight Loss with a Liquid Very Low-Calorie Diet Before Bariatric Surgery in Real Practice.

Objective: A preoperative very low-calorie diet (VLCD) is a common method to reduce weight before bariatric surgery. However, patient compliance and acceptability are not always known. The aim of this study is to evaluate the effectiveness, compliance, and acceptability of our regimen in a metropolitan academic quaternary care center.

Methods: Patients with a BMI < 50 kg/m and a BMI ≥ 50 kg/m were instructed to be on a liquid VLCD for 1 week and 2 weeks, respectively. The primary outcome was the amount of weight loss. Secondary outcomes were patient compliance and acceptability of either regimen using a questionnaire for hunger, satisfaction, desire, and deviation for solids.

Results: The study included 128 patients. Ninety-four patients were in the BMI < 50 kg/m group, and 34 patients were in the BMI ≥ 50 kg/m group. The BMI ≥ 50 kg/m group had a greater percentage of total weight loss (mean ± SD) than that of the BMI < 50 kg/m group without statistical differences (4.4 ± 1.3% vs. 3.8 ± 1.6%, p = 0.072). There were no statistical differences between the groups in terms of hunger, satisfaction with a liquid diet, or satisfaction of eating over drinking. However, hunger sensation (median [IQR]) tended to be higher in the BMI < 50 kg/m group than that in the BMI ≥ 50 kg/m group (2 [2] vs. 2 [2, 3]; p = 0.06). There was no statistical difference in the percentage of patient compliance between the groups (75.5% [n = 71] vs. 61.8% [n = 21], p = 0.18).

Conclusions: Preoperative liquid VLCD provided a modest amount of weight loss and showed a high rate of patient compliance and acceptability.