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

May combine two claims.

In older adults, leg lean mass fell significantly from energy balance to energy restriction and from energy restriction to energy restriction plus step reduction in both the whey protein and collagen peptide groups, with no between-group difference.

“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.”

May combine two claims.

Two weeks of energy restriction plus step reduction decreased average daily steps by approximately 84% and 90% in the whey protein and collagen peptide groups, respectively.

“2 wk of ER + SR resulted in a decrease in average daily steps by ∼84% and ∼90% (P < 0.001).”

May combine two claims.

Muscle protein synthesis was significantly elevated from energy restriction at recovery in the whey protein group and compared with the collagen peptide group (P = 0.05).

“MPS was significantly elevated from ER at RC in the WP group and in comparison to the CP group (P = 0.05).”

May combine two claims.

Fasted blood glucose increased significantly in the ER+SR phase compared with the EB and ER phases, and this elevation persisted into the RC phase.

“There was a significant increase in fasted blood glucose in ER + SR compared with EB and ER that remained elevated at RC (P < 0.001)”

May combine two claims.

Losses in leg lean mass mirrored losses in total lean body mass, with a significant reduction at energy restriction plus step reduction compared with energy restriction, and a rise at recovery compared with other times in the whey protein group but not the collagen peptide group.

“Losses in LLM mimicked losses in LBM with a significant reduction at ER + SR in comparison to ER that was increased at RC compared with other times in WP, but not in CP (Figure 3B).”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Subjects returned to taking similar steps during recovery as in energy balance, with no significant difference.

“Subjects returned to taking similar steps during RC (6336 ± 2348 and 8473 ± 3586) in both groups, showing no difference during RC compared with EB (P > 0.05).”

May combine two claims.

Integrated muscle protein synthesis rates fell during energy restriction and energy restriction plus step reduction in both groups, but rose during recovery only in the whey protein group.

“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).”

May combine two claims.

The addition of inactivity during the ER+SR phase resulted in elevated plasma insulin and impaired glucose handling.

“however, the addition of inactivity during ER + SR resulted in the elevation of plasma insulin and impairment of glucose handling.”

May combine two claims.

Collagen peptide supplementation did not increase leg lean mass or lean body mass during the RC phase.

“However, supplementation with CP did not result in increases in LLM or LBM during RC.”

May combine two claims.

Whey protein supplementation increased leg lean mass and lean body mass from the ER+SR phase during the RC phase.

“We also show that supplementation with WP increased LLM and LBM from ER + SR during RC.”

May combine two claims.

Whey protein stimulated recovery of muscle protein synthesis and increased leg lean mass during one week of return to habitual activity.

“Importantly, we show that WP was able to stimulate recovery of MPS and increase LLM in 1 wk of return to habitual activity”

Probably not a substantial claim: may not pass S3 (load-bearing).

Periods of inactivity and muscle disuse, such as bed rest and hospitalization, are more common in older persons.

“Periods of inactivity and muscle disuse, such as during bed rest and hospitalization or protracted illness, are more common in older persons (1).”

• cites [1] Naruishi, 2014, Predictors of improved functional outcome in elderly inpatients after rehabilitation: a retrospective study, Clin Interv Aging sourceNot checked yet

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May combine two claims.

Hospitalization-related loss of muscle mass and function can briefly worsen sarcopenia and lead to incomplete recovery, especially in older adults.

“The decline in muscle mass and function during hospitalization can transiently accelerate sarcopenic decline, resulting in incomplete recovery, particularly for older persons (2).”

• cites [2] Suetta, 2009, Effects of aging on human skeletal muscle after immobilization and retraining, J Appl Physiol (1985) sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

The trial was registered at clinicaltrials.gov as NCT03285737.

“The trial was registered at clinical trials.gov as NCT03285737.”

Classified as probably not a substantial claim.

Cutting total energy intake by 500 kcal/d below estimated requirements mimics the moderate energy restriction often seen in hospital.

“During the ER and ER + SR phases, a reduction in total energy intake of 500 kcal/d below the estimated energy requirement was applied to the diet to simulate a moderate energy restriction that is common during hospitalization (23).”

• cites [23] Konturek, 2015, Malnutrition in hospitals: it was, is now, and must not remain a problem!, Med Sci Monit sourceNot checked yet

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May combine two claims.

Hospitalization or illness can be accompanied by decreased appetite and food intake, leading to energy deficit and muscle loss.

“In addition to reduced ambulation, hospitalization or illness can be accompanied by a decrease in appetite and food intake, which can lead to an energy deficit and muscle loss (5).”

• cites [5] Tieland, 2011, Dietary protein intake in community-dwelling, frail, and institutionalized elderly people: scope for improvement, Eur J Nutr sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

The target of ≤750 steps per day resembles the step counts seen in hospitalized older patients.

“During the ER + SR phase, participants were instructed to reduce their daily step count to ≤750 steps/d, which is a daily step count similar to what is observed in older hospitalized patients (19).”

• cites [19] Fisher, 2011, Ambulatory activity of older adults hospitalized with acute medical illness, J Am Geriatr Soc sourceNot checked yet

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May combine two claims.

Whey protein supplementation alone increased leg lean mass and muscle protein synthesis during recovery from inactivity and low energy intake.

“but only supplemental WP augmented LLM and muscle protein synthesis during recovery from inactivity and a hypoenergetic state.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ethics approval came from the Hamilton Integrated Research Ethics Board, and the study followed human-subjects research standards.

“The study was approved by the Hamilton Integrated Research Ethics Board, and conformed to the standards for the use of human subjects in research”

Probably not a substantial claim: may not pass S3 (load-bearing).

Intra-assay coefficients of variation were <5% for all blood analyses.

“Intra-assay coefficients of variation were all <5% for all blood analyses.”

Classified as probably not a substantial claim.

Group assignment was hidden from both participants and researchers throughout the study and until analyses finished.

“Allocation was concealed from the participants and researchers for the duration of the study and until all analyses were complete.”

Classified as probably not a substantial claim. May combine two claims.

This was a randomized controlled trial with a double-blind, parallel-group design.

“The study was a double-blind, parallel-group, randomized controlled trial.”

Classified as probably not a substantial claim. May combine two claims.

About a quarter of body mass lost during an energy deficit is fat-free mass, and some of that is probably muscle.

“Typically, ∼25% of body mass lost in an energy deficit can be attributed to fat-free mass (6), some of which is likely muscle (7).”

• cites [6] Leidy, 2007, Higher protein intake preserves lean mass and satiety with weight loss in pre-obese and obese women, Obesity sourceNot checked yet

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• cites [7] Gallagher, 2000, Weight stability masks sarcopenia in elderly men and women, Am J Physiol Endocrinol Metab sourceNot checked yet

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May combine two claims.

Protein sources high in essential amino acids and leucine are known to raise muscle protein synthesis and might help prevent muscle mass and strength loss during inactivity.

“Supplementing the diet with protein sources rich in EAA and leucine is known to enhance rates of MPS (12,13), and may serve to offset losses in muscle mass and strength during periods of physical inactivity (14).”

• cites [12] Murphy, 2016, Leucine supplementation enhances integrative myofibrillar protein synthesis in free-living older men consuming lower- and higher-protein diets: a parallel-group crossover study, Am J Clin Nutr sourceNot checked yet

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• cites [13] Devries, 2015, Low-load resistance training during step-reduction attenuates declines in muscle mass and strength and enhances anabolic sensitivity in older men, Physiol Rep sourceNot checked yet

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• cites [14] English, 2016, Leucine partially protects muscle mass and function during bed rest in middle-aged adults, Am J Clin Nutr sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Fiber type analysis used at least 300 fibers, and cross-sectional area was measured from at least 50 fibers per type.

“fiber typing was conducted using ≥300 fibers, and cross-sectional area (CSA) was based on ≥50 fibers/fiber type.”

Probably not a substantial claim: may not pass S3 (load-bearing).

A single investigator manually verified the DXA analysis regions while blinded.

“The analysis regions were standard regions where the head, torso, arms, and legs were subdivided by the software, but were subsequently checked manually, in a blinded manner, by a single investigator (SYO).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Each testing day, the DXA scanner was calibrated using a 3-compartment Universal Whole Body DXA Phantom.

“The machine was calibrated each testing day with a 3-compartment Universal Whole Body DXA Phantom (Oscar, Jr; Orthometrix, Naples, FL).”

May combine two claims.

Collagen provides an isonitrogenous and isoenergetic comparison and has shown considerable anabolic properties in older adults, though these have been questioned.

“We selected collagen as a comparator as it provides an isonitrogenous and isoenergetic comparison (as opposed to carbohydrate, which is often used) (16), and as it has shown considerable and impressive anabolic properties in older adults (17) [which have been questioned (18)].”

• cites [16] Phillips, 2016, The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass, Nutr Metab (Lond) sourceNot checked yet

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• cites [17] Zdzieblik, 2015, Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial, Br J Nutr sourceNot checked yet

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• cites [18] Phillips, 2016, Exceptional body composition changes attributed to collagen peptide supplementation and resistance training in older sarcopenic men, Br J Nutr sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Whey is rich in essential amino acids, especially leucine, and consuming it boosts muscle protein synthesis.

“Whey protein has a high essential amino acid (EAA) content, particularly leucine, and its ingestion stimulates muscle protein synthesis (MPS) (11).”

• cites [11] Dickinson, 2011, Mammalian target of rapamycin complex 1 activation is required for the stimulation of human skeletal muscle protein synthesis by essential amino acids, J Nutr sourceNot checked yet

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May combine two claims.

Taking fewer steps lowers anabolic sensitivity to protein and reduces leg lean mass.

“We have shown that periods in which fewer steps are taken, as a model of inactivity but not outright muscle disuse, result in reductions in anabolic sensitivity to protein (3,4) and declines in leg lean mass (3).”

• cites [3] Breen, 2013, Two weeks of reduced activity decreases leg lean mass and induces “anabolic resistance” of myofibrillar protein synthesis in healthy elderly, J Clin Endocrinol Metab sourceNot checked yet

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• cites [4] McGlory, 2018, Failed recovery of glycemic control and myofibrillar protein synthesis with two weeks of physical inactivity in overweight, pre-diabetic older adults, J Gerontol A Biol Sci Med Sci sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Whey protein supplementation may protect leg lean mass during inactivity accompanied by a hypocaloric diet and may even improve recovery after returning to habitual activity.

“but that supplementation with WP may be protective on LLM from a bout of inactivity combined with a hypocaloric diet and even enhance recovery following return to habitual activity.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Existing literature using a bedrest model found a significant mediating effect of bed rest on increases in systemic inflammation after 35 days of inactivity.

“These findings are congruent with existing literature using a bedrest model in which the authors found a significant mediating effect of bed rest on increases in systemic inflammation following 35 d of inactivity (39).”

• cites [39] Biolo, 2008, Positive energy balance is associated with accelerated muscle atrophy and increased erythrocyte glutathione turnover during 5 wk of bed rest, Am J Clin Nutr sourceNot checked yet

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May combine two claims.

The pronounced increase in leg lean mass and lean body mass with whey protein supplementation supports raising protein intake in older adults to overcome the age-related heightened anabolic resistance to protein feeding.

“The pronounced increase in LLM and LBM with WP supplementation provides support for increasing protein intake in older adults in an effort to overcome the heighted anabolic resistance to protein feeding that occurs with age (38).”

• cites [38] Moore, 2015, Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men, J Gerontol A Biol Sci Med Sci sourceNot checked yet

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Classified as probably not a substantial claim. May combine two claims.

The progression of dietary and activity phases in this study was a strength of the protocol because it allowed determination of the effects of energy restriction alone, and in combination with step reduction and high protein intake, on muscle metabolism in older adults.

“The progression of dietary and activity phases in the present study was a strength of this protocol as it allowed us to determine the effects of ER alone, and in combination with ER + SR with high protein intake, on muscle metabolism in older adults.”

May combine two claims.

All participants were healthy and free of chronic conditions, which restricts how far the intervention can be applied to older persons with common clinical chronic conditions.

“Second, all the participants in the current study were healthy and free of any chronic condition, thus limiting the applicability of the intervention to older persons with clinically prevalent chronic conditions.”

May combine two claims.

The study did not directly measure muscle protein breakdown rates, so the relative contributions of muscle protein synthesis and breakdown to changes in lean body mass and leg lean mass are unknown.

“First, we did not directly measure rates of muscle protein breakdown, and therefore the relative contributions of MPS and muscle protein breakdown to changes in LBM and LLM are unknown.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

If energy restriction and step reduction harm skeletal muscle strongly in healthy older adults, then a compromised older population would likely experience greater muscle loss and worse glycemic control.

“However, if the detrimental effects of ER and SR on skeletal muscle are significantly pronounced in a cohort of healthy older adults, we propose that losses in muscle mass and impairments in glycemic control would be worsened in a compromised older adult population as we have reported (4).”

• cites [4] McGlory, 2018, Failed recovery of glycemic control and myofibrillar protein synthesis with two weeks of physical inactivity in overweight, pre-diabetic older adults, J Gerontol A Biol Sci Med Sci sourceNot checked yet

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