A systematic review of the separate and combined effects of energy restriction and exercise on fat‐free mass in middle‐aged and older adults: Implications for sarcopenic obesity

Abstract

PurposeThis systematic review assessed the effects of energy restriction (ER) and exercise (EX) on fat‐free mass (FFM) in overweight and obese middle‐aged and older adults.MethodsPubmed was searched using “weight loss or energy restriction” AND “skeletal muscle or body composition” as keywords, with limitations “human” and “middle‐aged and aged.” 52 studies met inclusion criteria that included men and/or postmenopausal women aged ≥ 50 y, BMI > 25 kg/m2, and interventions ≥ 8 wk. Body weight (BW) loss was induced via ER, ER+EX, or EX. ER was achieved by counseling without (n=35) or with (n=7) some food provided, or all food provided (n=3). EX included aerobic (n=31), resistance (n=3), or both (n=5). Results are reported as % of the ER, ER+EX, or EX groups that had a specified change in BW and FFM, since insufficient data were provided to perform a meta‐analysis.Results94% of the ER groups and 89% of the ER+EX groups lost ≥ 5 kg BW. 75% of the ER groups, but only 30% of the ER+EX groups, lost ≥ 1.5 kg FFM. 81% and 39% of the ER and ER+EX groups, respectively, lost ≥ 15% of BW as FFM. The EX groups had modest BW (94% lost < 5 kg) and FFM (100% lost < 1.5 kg) losses.ConclusionExercise is an effective tool to help middle‐aged and older overweight and obese adults preserve FFM after moderate energy restriction‐induced weight loss, and may be effective in combating sarcopenic obesity.Support: T32AG025671; US Whey Protein Research ConsortiumGrant Funding Source: T32AG025671; US Whey Protein Research Consortium