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.
RCT Entities:
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.
Authors: Caoileann H Murphy; Tyler A Churchward-Venne; Cameron J Mitchell; Nathan M Kolar; Amira Kassis; Leonidas G Karagounis; Louise M Burke; John A Hawley; Stuart M Phillips Journal: Am J Physiol Endocrinol Metab Date: 2015-03-03 Impact factor: 4.310
Authors: E M P Backx; M Tieland; K J Borgonjen-van den Berg; P R Claessen; L J C van Loon; L C P G M de Groot Journal: Int J Obes (Lond) Date: 2015-10-16 Impact factor: 5.095
Authors: Zoltan Ungvari; Zsuzsanna Tucsek; Danuta Sosnowska; Peter Toth; Tripti Gautam; Andrej Podlutsky; Agnes Csiszar; Gyorgy Losonczy; M Noa Valcarcel-Ares; William E Sonntag; Anna Csiszar Journal: J Gerontol A Biol Sci Med Sci Date: 2012-12-13 Impact factor: 6.053
Authors: Anna Csiszar; Danuta Sosnowska; Zsuzsanna Tucsek; Tripti Gautam; Peter Toth; Gyorgy Losonczy; Ricki J Colman; Richard Weindruch; Rozalyn M Anderson; William E Sonntag; Zoltan Ungvari Journal: J Gerontol A Biol Sci Med Sci Date: 2012-08-17 Impact factor: 6.053