Preserved Fat-Free Mass after Gastric Bypass and Duodenal Switch

• Published in: Obesity surgery 2017-07, Vol.27 (7), p.1735-1740
• Main Authors: Skogar, Martin, Holmbäck, Ulf, Hedberg, Jakob, Risérus, Ulf, Sundbom, Magnus
• Format: Article
• Language: English
• Subjects: Adult; Basal Metabolism - physiology; Body composition; Body Composition - physiology; Case-Control Studies; Gastric Bypass - statistics & numerical data; Gastrointestinal surgery; Humans; Medicine; Medicine & Public Health; Middle Aged; Obesity; Obesity, Morbid - epidemiology; Obesity, Morbid - surgery; Original Contributions; Surgery; Surgical outcomes; Weight control
• ISSN: 0960-8923; 1708-0428; 1708-0428
• DOI: 10.1007/s11695-016-2476-6

Background 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. Objectives This study aims to examine body composition and RMR in patients after RYGB and BPD/DS and in non-operated controls. Methods Body 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/m 2 . Results FFM% 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). Conclusion Weight-stable patients with BMI 28–35 kg/m 2 after RYGB and BPD/DS have a body composition and RMR similar to that of non-operated individuals within the same BMI interval.