Resistance Training and Protein Supplementation Increase Strength After Bariatric Surgery: A Randomized Controlled Trial.

OBJECTIVE: Physical activity and dietary regimens to optimize health outcomes after bariatric surgery are not well known. This study aimed to determine whether resistance training with dietary protein supplementation is effective in maintaining body composition and physical fitness after obesity surgery.

METHODS: Seventy-six women with obesity undergoing Roux-en-Y gastric bypass were randomly assigned at the time of surgery to receive either usual care (controls [CON], n = 22), usual care and additional (whey) protein intake (PRO, n = 31), or usual care, additional protein intake, and supervised strength training for 18 weeks (PRO+EX, n = 23). The primary outcome was pre- to 6-month postsurgery change in lean body mass (by dual-energy x-ray absorptiometry). Secondary outcomes included changes in muscle strength (by one-repetition maximum testing).

RESULTS: Loss over time in lean body mass did not differ between groups (CON: mean,-8.8 kg; 95% CI: -10.1 to -7.5 kg; PRO: mean, -8.2 kg; 95% CI: -9.3 to -7.1 kg; PRO+EX: mean, -7.7 kg; 95% CI: -9.0 to -6.5 kg; P = 0.899). The increase in relative lower-limb muscle strength was higher in the PRO+EX group (+0.6 [0.3 to 0.8]) versus +0.1 (-0.1 to 0.4) and +0.2 (0.0 to 0.4) kg/kg body mass in CON and PRO groups, respectively (P = 0.021).

CONCLUSIONS: Loss in muscle strength observed after bariatric surgery can be overcome by resistance training with additional protein intake.