Effects of high‐protein weight loss diets on fat‐free mass changes in older adults: a systematic review (371.5)

Abstract

With advancing age, many adults experience increased body weight (BW) and fat mass (FM) but decreased fat‐free mass (FFM). Purposeful moderate dietary energy restriction (ER) (500‐750 kcal/d E deficits) reduces BW and FM, but also FFM. High protein (HP) vs. normal protein (NP) intake during ER may more effectively retain FFM, but this issue requires systematic evaluation in older adults. We conducted a systematic review of randomized control trials (RCT) to assess the effects of protein intake on ER‐induced changes in FFM in adults mean age 50+ years. Eighteen RCT were systematically evaluated with HP defined as either 1) > 25% of the total E from protein; or 2) > 1 g protein/(kg[[Unsupported Character ‐ Symbol Font ř]]d). The median protein intakes of the HP and NP groups were 30 and 18 % of the total E intake (ranges: 25‐40 and 15‐20), respectively, and 1.53 and 0.87 g protein/(kg[[Unsupported Character ‐ Symbol Font ř]]d) (ranges: 1.04‐1.89 and 0.66‐0.99), respectively. With dietary protein expressed as % of E intake, fewer HP vs. NP groups lost 蠅 30% of BW as FFM (20 vs. 44 % of groups) and more HP vs. NP groups lost < 20 % of BW as FFM (40 vs. 17 % of groups). Similarly, using g protein/(kg[[Unsupported Character ‐ Symbol Font ř]]d), fewer HP vs. NP groups lost 蠅 30% of BW as FFM (19 vs. 44 % of groups) and more HP vs. NP groups lost < 20 % of BW as FFM (44 vs. 12 % of groups). These findings indicate that old adults can more effectively retain FFM during weight loss when they consume a high‐protein diet.Grant Funding Source: Support by Purdue Univ Ingest Behav Res Ctr