Very low-calorie diet in candidates for bariatric surgery: change in body composition during rapid weight loss

Marcela Pires Serafim,Marco Aurelio Santo,Alexandre Vieira Gadducci,Veruska Magalhães Scabim,Ivan Cecconello,Roberto De Cleva

doi:10.6061/clinics/2019/e560

Abstract

OBJECTIVE:To analyze the changes in the body composition of morbidly obese patients induced by a very low-calorie diet.METHODS:We evaluated 120 patients selected from a university hospital. Body composition was assessed before and after the diet provided during hospitalization, and changes in weight, body mass index, and neck, waist and hip circumferences were analyzed. Bioimpedance was used to obtain body fat and fat-free mass values. The data were categorized by gender, age, body mass index and diabetes diagnosis.RESULTS:The patients consumed the diet for 8 days. They presented a 5% weight loss (without significant difference among groups), which represented an 85% reduction in body fat. All changes in body circumference were statistically significant. There was greater weight loss and a greater reduction of body fat in men, but the elderly showed a significantly higher percentage of weight loss and greater reductions in body fat and fat-free mass. Greater reductions in body fat and fat-free mass were also observed in superobese patients. The changes in the diabetic participants did not differ significantly from those of the non-diabetic participants.CONCLUSIONS:The use of a VLCD before bariatric surgery led to a loss of weight at the expense of body fat over a short period, with no significant differences in the alteration of body composition according to gender, age, body mass index and diabetes status.

Highlights

Morbid obesity is a risk factor for higher mortality during the preoperative period of bariatric surgery [1], and it requires care that includes pharmacological monitoring, anesthesia [2] and standard ventilator use [3]
Acute or chronic diseases associated with excessive water retention, subjects with weight loss greater than 5% before hospitalization and those who did not agree to participate in this study were excluded
In terms of weight loss, diet is an essential factor in routine care for the morbidly obese, and the impact of the very low-calorie diet (VLCD) on changes in the body composition of morbidly obese individuals and its benefits during the perioperative period of bariatric surgery have been demonstrated [24,28]

Summary

Introduction

Morbid obesity is a risk factor for higher mortality during the preoperative period of bariatric surgery [1], and it requires care that includes pharmacological monitoring, anesthesia [2] and standard ventilator use [3]. Several benefits have been demonstrated for weight loss between 5 and 10% [4] through conventional clinical treatments, such as a significant decrease in visceral adipose tissue [2,4] and liver volume [2] and decreases in risk factors [3], surgical risk [5,6], blood loss [2], length of surgery [4,6] and length of hospital stay [7].

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Results

Discussion

Conclusion