Background: Changes in body composition after bariatric surgery such as a sustained loss of body fat are often associated with an inevitable loss of fat free mass. This can contribute to an undesirable disturbance in resting metabolic rate and weight maintenance. Our aim was to study changes in body composition in a multiethnic Asian cohort following bariatric surgery and to identify differences between laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass.
Methods: A retrospective review of prospectively collected data on 295 patients who underwent either laparoscopic sleeve gastrectomy (256 patients) or laparoscopic Roux-en-Y gastric bypass (39 patients) was performed. Body composition variables were measured with the analyzer, GAIA 359 PLUS, which included the parameters; total body weight, body mass index, excess weight, basal metabolic rate, fat-free mass, fat mass, and total body water.
Results: There were no statistical differences in gender, ethnicity, age, weight, height, and body mass index between laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass. At each time point (6, 12, 24, and 36 months) post-operation, there was no significant differences in % total body weight loss, basal metabolic rate, fat mass, fat percentage, and total body water between sleeve gastrectomy and bypass patients. There was significant difference (p < 0.05) in fat free mass only at 3 years post-operation, with sleeve gastrectomy patients having 9.79 kg less fat-free mass than bypass patients. However, after multivariate analysis, we found no statistically significant differences.
Conclusion: Sleeve gastrectomy and gastric bypass seemed to give similar changes to body composition.
Keywords: Body composition; Gastric bypass; Sleeve gastrectomy.