Preserved Fat-Free Mass after Gastric Bypass and Duodenal Switch

Martin Skogar,Magnus Sundbom,Ulf Risérus,Ulf Holmbäck,Jakob Hedberg

doi:10.1007/s11695-016-2476-6

Abstract

BackgroundConcerns for the possibility of an excessive loss of fat-free mass (FFM) and resting metabolic rate (RMR) after bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and duodenal switch (BPD/DS), have been raised.ObjectivesThis study aims to examine body composition and RMR in patients after RYGB and BPD/DS and in non-operated controls.MethodsBody composition and RMR were studied with Bod Pod and indirect calorimetry in weight-stable RYGB (n = 15) and BPD/DS patients (n = 12) and compared with non-operated controls (n = 17). All patients were 30–55 years old and weight stable with BMI 28–35 kg/m2.ResultsFFM% was 58% (RYGB), 61% (BPD/DS), and 58% (controls). Body composition did not differ after RYGB and BPD/DS compared to controls, despite 27 and 40% total body weight loss, respectively. No difference in RMR or RMR/FFM was observed (1539, 1617, and 1490 kcal/24 h; and 28.9, 28.4, and 28.8 kcal/24 h/kg).ConclusionWeight-stable patients with BMI 28–35 kg/m2 after RYGB and BPD/DS have a body composition and RMR similar to that of non-operated individuals within the same BMI interval.

Highlights

Long-term results after bariatric surgery include sustained weight loss, high remission rates in diabetes, improved cardiovascular risk profile, and improved quality of life [1,2,3,4]
Preoperative BMI was higher in the bypass (RYGB) and duodenal switch (BPD/DS) group compared with the Roux-en-Y gastric bypass (RYGB) group
There were no significant differences in fat-free mass (FFM), fat mass (FM), FFM/FM ratio, FFM%, or FM% between the three groups (Table 2)

Summary

Introduction

Long-term results after bariatric surgery include sustained weight loss, high remission rates in diabetes, improved cardiovascular risk profile (reduced hypertension and dyslipidemia), and improved quality of life [1,2,3,4]. Roux-en-Y gastric bypass (RYGB) is a common surgical procedure for the treatment of severe obesity (body mass index (BMI) > 35 kg/m2) worldwide. In Sweden, RYGB represents 82% of all bariatric procedures in 2015 [5], while duodenal switch (BPD/DS) is mostly offered in patients with super obesity (BMI > 50 kg/m2). Concerns for the possibility of malnutrition and an excessive loss of FFM after RYGB and especially BPD/DS have been raised and the safety in regard to nutrition and body composition are considered potentially problematic [8]. Concerns for the possibility of an excessive loss of fat-free mass (FFM) and resting metabolic rate (RMR) after bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and duodenal switch (BPD/DS), have been raised

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Conclusion