A randomized controlled trial of the impact of protein supplementation on leg lean mass and integrated muscle protein synthesis during inactivity and energy restriction in older persons.
Am J Clin Nutr
; 108(5): 1060-1068, 2018 11 01.
Article
em En
| MEDLINE
| ID: mdl-30289425
ABSTRACT
Background:
In older persons, muscle loss is accelerated during physical inactivity and hypoenergetic states, both of which are features of hospitalization. Protein supplementation may represent a strategy to offset the loss of muscle during inactivity, and enhance recovery on resumption of activity.Objective:
We aimed to determine if protein supplementation, with proteins of substantially different quality, would alleviate the loss of lean mass by augmenting muscle protein synthesis (MPS) while inactive during a hypoenergetic state.Design:
Participants (16 men, mean ± SD age 69 ± 3 y; 15 women, mean ± SD age 68 ± 4 y) consumed a diet containing 1.6 g protein · kg-1 · d-1, with 55% ± 9% of protein from foods and 45% ± 9% from supplements, namely, whey protein (WP) or collagen peptides (CP) 30 g each, consumed 2 times/d. Participants were in energy balance (EB) for 1 wk, then began a period of energy restriction (ER; -500 kcal/d) for 1 wk, followed by ER with step reduction (ER + SR; <750 steps/d) for 2 wk, before a return to habitual activity in recovery (RC) for 1 wk.Results:
There were significant reductions in leg lean mass (LLM) from EB to ER, and from ER to ER + SR in both groups (P < 0.001) with no differences between WP and CP or when comparing the change from phase to phase. During RC, LLM increased from ER + SR, but in the WP group only. Rates of integrated muscle protein synthesis decreased during ER and ER + SR in both groups (P < 0.01), but increased during RC only in the WP group (P = 0.05).Conclusions:
Protein supplementation did not confer a benefit in protecting LLM, but only supplemental WP augmented LLM and muscle protein synthesis during recovery from inactivity and a hypoenergetic state. This trial was registered at http//www.clinicaltrials.gov as NCT03285737.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
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Alimentacao
Base de dados:
MEDLINE
Assunto principal:
Biossíntese de Proteínas
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Ingestão de Energia
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Músculo Esquelético
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Suplementos Nutricionais
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Proteínas do Soro do Leite
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Atividade Motora
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Proteínas Musculares
Tipo de estudo:
Clinical_trials
Limite:
Aged
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Female
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Humans
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Male
Idioma:
En
Revista:
Am J Clin Nutr
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Canadá