Characterization of bariatric surgery patients: evaluation of body composition and metabolism

Undergraduates: Shawn Ahuja, Eric T. Trexler, Malia M. Blue, Katie R. Hirsch, Alexis A. Pihoker, Meredith G. Mock, Kara A. Anderson

Faculty Advisor: Abbie Smith-Ryan
Department: Exercise & Sport Science

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Purpose: To evaluate the effects of protein supplementation compared to standard care in bariatric surgery patients. Methods: Thirteen patients (Age: 42.9 ¿¿ 10.4 yrs; Height: 162.5 ¿¿ 6.2 cm; Weight: 323.2 ¿¿ 72.9 lbs) volunteered for the study. Following random assignment to protein supplementation (PRO; n=4) or standard of care (SOC; n=3), seven patients completed a follow-up visit 3 weeks post-surgery. Resting metabolic rate (RMR) was determined via portable indirect calorimetry. Body composition [fat mass (FM), fat free mass (FFM), and percent body fat (%BF)] was measured via bioelectrical impedance spectroscopy. Functional fitness was determined from the 30-second chair stand test. Results: Baseline mean RMR was 2120.7 ¿¿ 574.1 kcals. Mean FM=144.3 ¿¿ 36.4 lbs, FFM=178.9 ¿¿ 48.2 lbs, and %BF = 44.8 ¿¿ 6.1%. Average chair stand was 12.2 ¿¿ 3.7 repetitions. While there was no significant difference in RMR three weeks post-surgery (p=0.057), RMR in PRO was generally maintained (-26.3 ¿¿ 175 kcals) and decreased in SOC (-552 ¿¿ 275 kcals). There were no significant differences for FM (-5.3 ¿¿ 9.6 lbs; p=0.321), FFM (-18.1 ¿¿ 10.2 lbs; p=0.139), or %BF (-1.2 ¿¿ 2.1 %; p=0.653). There was no difference in chair stand results between groups (p=0.627). Discussion: Despite being statistically nonsignificant, an RMR difference of over 500 kcals is meaningful in the context of weight loss. Reduced RMR may facilitate weight regain or prevent weight loss due to decreased caloric expenditure.