waxonsexon
New member
Authors
Thomas M Longland,
Sara Y Oikawa,
Cameron J Mitchell,
Michaela C Devries, and
Stuart M Phillips*
Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
↵*To whom correspondence should be addressed. E-mail: phillis@mcmaster.ca.
↵1 Funded by the Natural Science and Engineering Research Council of Canada (grant no. RGPIN-2015-04613 to SMP and postgraduate scholarship–doctoral to CJM). This is a free access article, distributed under terms (http://www.nutrition.org/publications/guidelines-and-policies/license/) that permit unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
↵2 The funder had no role in the study design, analyses, or interpretation of the results.
Abstract
Background: A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise.
Objective: The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition.
Design: We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (∼40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg−1 · d−1) control diet (CON) or a higher-protein (2.4 g · kg−1 · d−1) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention.
Results: As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: −4.8 ± 1.6 kg; CON: −3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = −0.34, P = 0.03).
Conclusions: Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg−1 · d−1 was more effective than consumption of a diet containing 1.2 g protein · kg−1 · d−1 in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.
fue validado hace poco; igual no encuentro mucha concordancia por que todos sabemos que aumentar masa muscular mientra definimos es imposible y acá sale con resultados.
Thomas M Longland,
Sara Y Oikawa,
Cameron J Mitchell,
Michaela C Devries, and
Stuart M Phillips*
Department of Kinesiology, Exercise Metabolism Research Group, McMaster University, Hamilton, Canada
↵*To whom correspondence should be addressed. E-mail: phillis@mcmaster.ca.
↵1 Funded by the Natural Science and Engineering Research Council of Canada (grant no. RGPIN-2015-04613 to SMP and postgraduate scholarship–doctoral to CJM). This is a free access article, distributed under terms (http://www.nutrition.org/publications/guidelines-and-policies/license/) that permit unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
↵2 The funder had no role in the study design, analyses, or interpretation of the results.
Abstract
Background: A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise.
Objective: The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition.
Design: We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (∼40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg−1 · d−1) control diet (CON) or a higher-protein (2.4 g · kg−1 · d−1) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention.
Results: As a result of the intervention, LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: −4.8 ± 1.6 kg; CON: −3.5 ± 1.4kg; P < 0.05). All measures of exercise performance improved similarly in the PRO and CON groups as a result of the intervention with no effect of protein supplementation. Changes in serum cortisol during the intervention were associated with changes in body fat (r = 0.39, P = 0.01) and LBM (r = −0.34, P = 0.03).
Conclusions: Our results showed that, during a marked energy deficit, consumption of a diet containing 2.4 g protein · kg−1 · d−1 was more effective than consumption of a diet containing 1.2 g protein · kg−1 · d−1 in promoting increases in LBM and losses of fat mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359.
fue validado hace poco; igual no encuentro mucha concordancia por que todos sabemos que aumentar masa muscular mientra definimos es imposible y acá sale con resultados.
