TY - JOUR
T1 - The effects of a higher protein intake during energy restriction on changes in body composition and physical function in older women
AU - Mojtahedi, Mina C.
AU - Thorpe, Matthew P.
AU - Karampinos, Dimitrios C.
AU - Johnson, Curtis L.
AU - Layman, Donald K.
AU - Georgiadis, John G.
AU - Evans, Ellen M.
PY - 2011/11
Y1 - 2011/11
N2 - Background. The purpose of this double-blind randomized clinical trial was to compare the relative effectiveness of a higher protein and conventional carbohydrate intake during weight loss on body composition and physical function in older women. Methods. Thirty-one overweight or obese, postmenopausal women (mean ± SD: age 65.2 ± 4.6 years, body mass index 33.7 ± 4.9 kg/m 2) were prescribed a reduced calorie diet (1,400 kcal/day; 15%, 65%, 30% energy from protein, carbohydrate, and fat, respectively) and randomly assigned to 2 × 25 g/day whey protein (PRO n = 15) or maltodextrin (CARB n = 16) supplementation for 6 months. Lean soft tissue (LST) via dual-energy X-ray absorptiometry; thigh muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue with magnetic resonance imaging; knee strength with isokinetic dynamometry; balance and physical function with a battery of performance tests.Results.PRO lost more weight than CARB (-8.0% ± 6.2%,-4.1% ± 3.6%, p =. 059; respectively). Changes in LST, %LST, and strength, balance, or physical performance measures did not differ between groups (all p >. 05). Weight to leg LST ratio improved more in PRO versus CARB (-4.6 ± 3.6%,-1.8 ± 2.6%, p =. 03). PRO lost 4.2% more muscle (p =. 01), 10.9% more SAT (p =. 02), and 8.2% more intermuscular adipose tissue (p =. 03) than CARB. Relative to thigh volume changes, PRO gained 5.8% more muscle (p =. 049) and lost 3.8% greater SAT (p =. 06) than CARB. Weight to leg LST ratio (r 2 =. 189, p =. 02) and SAT (r 2 =. 163, p =. 04) predicted improved up and go, relative muscle (r 2 =. 238, p =. 01) and SAT (r 2 =. 165, p =. 04) predicted improved transfer test, and %LST predicted improved balance (r 2 =. 179, p =. 04). Conclusions. A higher protein intake during caloric restriction maintains muscle relative to weight lost, which in turn enhances physical function in older women.
AB - Background. The purpose of this double-blind randomized clinical trial was to compare the relative effectiveness of a higher protein and conventional carbohydrate intake during weight loss on body composition and physical function in older women. Methods. Thirty-one overweight or obese, postmenopausal women (mean ± SD: age 65.2 ± 4.6 years, body mass index 33.7 ± 4.9 kg/m 2) were prescribed a reduced calorie diet (1,400 kcal/day; 15%, 65%, 30% energy from protein, carbohydrate, and fat, respectively) and randomly assigned to 2 × 25 g/day whey protein (PRO n = 15) or maltodextrin (CARB n = 16) supplementation for 6 months. Lean soft tissue (LST) via dual-energy X-ray absorptiometry; thigh muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue with magnetic resonance imaging; knee strength with isokinetic dynamometry; balance and physical function with a battery of performance tests.Results.PRO lost more weight than CARB (-8.0% ± 6.2%,-4.1% ± 3.6%, p =. 059; respectively). Changes in LST, %LST, and strength, balance, or physical performance measures did not differ between groups (all p >. 05). Weight to leg LST ratio improved more in PRO versus CARB (-4.6 ± 3.6%,-1.8 ± 2.6%, p =. 03). PRO lost 4.2% more muscle (p =. 01), 10.9% more SAT (p =. 02), and 8.2% more intermuscular adipose tissue (p =. 03) than CARB. Relative to thigh volume changes, PRO gained 5.8% more muscle (p =. 049) and lost 3.8% greater SAT (p =. 06) than CARB. Weight to leg LST ratio (r 2 =. 189, p =. 02) and SAT (r 2 =. 163, p =. 04) predicted improved up and go, relative muscle (r 2 =. 238, p =. 01) and SAT (r 2 =. 165, p =. 04) predicted improved transfer test, and %LST predicted improved balance (r 2 =. 179, p =. 04). Conclusions. A higher protein intake during caloric restriction maintains muscle relative to weight lost, which in turn enhances physical function in older women.
KW - Body composition
KW - Dietary protein
KW - Older women
KW - Physical function
KW - Weight loss
UR - https://www.scopus.com/pages/publications/80054943401
U2 - 10.1093/gerona/glr120
DO - 10.1093/gerona/glr120
M3 - Article
C2 - 21798863
AN - SCOPUS:80054943401
SN - 1079-5006
VL - 66 A
SP - 1218
EP - 1225
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 11
ER -