Background

Resting energy expenditure (REE) is a measurement of whole-body metabolism. There is increasing interest in understanding how variations in REE are related to successful weight loss after surgery. The purpose of this study was to determine if there was an association between REE and mean percent total weight loss (%TWL) following various bariatric procedures.

Methods

A prospectively maintained database was retrospectively reviewed to identify all patients who underwent bariatric surgery and metabolic testing at our institution between September 2016 and October 2021. Indirect Calorimetry was used to measure REE pre and postoperatively. Data for baseline patient characteristics, REE, and %TWL was analyzed for comparison.

Results

A total of 58 patients (45 female, 13 male) met inclusion criteria. The types of bariatric procedures performed included duodenal switch (n=16), gastric bypass (n=10), and sleeve gastrectomy (n=32). Baseline patient characteristics were similar among the subjects. Although there was no statistically significant difference in the mean %TWL at 6 months (p=0.08), the mean %TWL was higher in patients who underwent a duodenal switch (27.2%±5.1) or gastric bypass (28.5%±5.8) when compared to sleeve gastrectomy (21.9%±6.9) (table 1). Interestingly, sleeve gastrectomy patients had a significant decrease in their REE at 6 months (p=0.02), while duodenal switch (p=0.20) and gastric bypass (p=0.07) patients did not (table 2).

Conclusions

Sleeve gastrectomy had lower mean %TWL than both duodenal switch and gastric bypass at 6 months. Sleeve gastrectomy patients also had a significant decrease in their postoperative REE, which may have a role in their lower mean %TWL.