Preoperative high respiratory quotient correlates with lower weight loss after bariatric surgery

Background The respiratory coefficient (RQ), as determined by indirect calorimetry (IC), classifies diet as being carbohydrate rich (RQ = 0.7–0.8), fat rich (RQ = 0.9–1.0), or overfeeding (RQ > 1). We hypothesized that preoperative RQ may be associated with weight-loss outcomes after bariatric surgery. Methods From 2016 to 2018, 137 obese patients were enrolled in a Bariatric Registry and underwent dietary and behavioral counseling, followed by preoperative IC. Resting energy expenditure (REE) and RQ of all patients was measured. Patients were classified as over-feeders (OF; 42, 31%) with RQ > 1 or non-over-feeders (NOF; 95, 69%) with RQ