scholarly journals Influence of Protein Intake and Timing on Whole Body Protein Turnover in Middle‐Aged Men and Women

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Megan Colletto ◽  
Nancy Rodriguez
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Middle Aged ◽  
Body Protein ◽  
Men And Women

Effect of variable protein intake on whole-body protein turnover in young men and women

1995 ◽  
Vol 61 (1) ◽  
pp. 69-74 ◽  
Author(s):  
D L Pannemans ◽  
D Halliday ◽  
K R Westerterp ◽  
A D Kester
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Young Men ◽  
Whole Body ◽  
Body Protein ◽  
Men And Women

Dietary protein requirements and body protein metabolism in endurance-trained men

1989 ◽  
Vol 66 (6) ◽  
pp. 2850-2856 ◽  
Author(s):  
C. N. Meredith ◽  
M. J. Zackin ◽  
W. R. Frontera ◽  
W. J. Evans
Keyword(s):  
Dietary Protein ◽  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Middle Aged ◽  
Body Protein ◽  
Protein Requirements ◽  
High Quality Protein ◽  
Effect Of Age ◽  
Lower Physical Activity

The effects of regular submaximal exercise on dietary protein requirements, whole body protein turnover, and urinary 3-methylhistidine were determined in six young (26.8 +/- 1.2 yr) and six middle-aged (52.0 +/- 1.9 yr) endurance-trained men. They consumed 0.6, 0.9, or 1.2 g.kg-1.day-1 of high-quality protein over three separate 10-day periods, while maintaining training and constant body weight. Nitrogen measurements in diet, urine, and stool and estimated sweat and miscellaneous nitrogen losses showed that they were all in negative nitrogen balance at a protein intake of 0.6 g.kg-1.day-1. The estimated protein requirement was 0.94 +/- 0.05 g.kg-1.day-1 for the 12 men, with no effect of age. Whole body protein turnover, using [15N]glycine as a tracer, and 3-methylhistidine excretion were not different in the two groups, despite lower physical activity of the middle-aged men. Protein intake affected whole body protein flux and synthesis but not 3-methylhistidine excretion. These data show that habitual endurance exercise was associated with dietary protein needs greater than the current Recommended Dietary Allowance of 0.8 g.kg-1.day-1. However, whole body protein turnover and 3-methylhistidine excretion were not different from values reported for sedentary men.

scholarly journals Protein intake and yoga influence whole body protein turnover in middle‐aged women

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Megan Colletto ◽  
Jose Rodriguez ◽  
Jeffrey DelFavero ◽  
Nancy Rodriguez
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Middle Aged ◽  
Body Protein

scholarly journals Impact of habituated dietary protein intake on fasting and postprandial whole-body protein turnover and splanchnic amino acid metabolism in elderly men: a randomized, controlled, crossover trial

2020 ◽  
Vol 112 (6) ◽  
pp. 1468-1484 ◽  
Author(s):  
Grith Højfeldt ◽  
Jacob Bülow ◽  
Jakob Agergaard ◽  
Ali Asmar ◽  
Peter Schjerling ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Turnover ◽  
Protein Intake ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
High Protein ◽  
Whole Body ◽  
Body Protein ◽  
Protein Absorption ◽  
Fasted State

ABSTRACT Background Efficacy of protein absorption and subsequent amino acid utilization may be reduced in the elderly. Higher protein intakes have been suggested to counteract this. Objectives We aimed to elucidate how habituated amounts of protein intake affect the fasted state of, and the stimulatory effect of a protein-rich meal on, protein absorption, whole-body protein turnover, and splanchnic amino acid metabolism. Methods Twelve men (65–70 y) were included in a double-blinded crossover intervention study, consisting of a 20-d habituation period to a protein intake at the RDA or a high amount [1.1 g · kg lean body mass (LBM)−1 · d−1 or >2.1 g · kg LBM−1 · d−1, respectively], each followed by an experimental trial with a primed, constant infusion of D8-phenylalanine and D2-tyrosine. Arterial and hepatic venous blood samples were obtained after an overnight fast and repeatedly 4 h after a standardized meal including intrinsically labeled whey protein concentrate and calcium-caseinate proteins. Blood was analyzed for amino acid concentrations and phenylalanine and tyrosine tracer enrichments from which whole-body and splanchnic amino acid and protein kinetics were calculated. Results High (compared with the recommended amount of) protein intake resulted in a higher fasting whole-body protein turnover with a resultant mean ± SEM 0.03 ± 0.01 μmol · kg LBM−1 · min−1 lower net balance (P < 0.05), which was not rescued by the intake of a protein-dense meal. The mean ± SEM plasma protein fractional synthesis rate was 0.13 ± 0.06%/h lower (P < 0.05) after habituation to high protein. Furthermore, higher fasting and postprandial amino acid removal were observed after habituation to high protein, yielding higher urea excretion and increased phenylalanine oxidation rates (P < 0.01). Conclusions Three weeks of habituation to high protein intake (>2.1 g protein · kg LBM−1 · d−1) led to a significantly higher net protein loss in the fasted state. This was not compensated for in the 4-h postprandial period after intake of a meal high in protein. This trial was registered at clinicaltrials.gov as NCT02587156.

scholarly journals The Effect of an Increase of Protein Intake on Whole-Body Protein Turnover in Elderly Women Is Tracer Dependent

1997 ◽  
Vol 127 (9) ◽  
pp. 1788-1794 ◽  
Author(s):  
Daphne L. E. Pannemans ◽  
Anton J. M. Wagenmakers ◽  
Klaas R. Westerterp, ◽  
Gertjan Schaafsma ◽  
Dave Halliday
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Elderly Women ◽  
Whole Body ◽  
Body Protein

Influence of Dietary Protein Intake on Whole-Body Protein Turnover in Humans

Diabetes Care ◽  
1991 ◽  
Vol 14 (12) ◽  
pp. 1189-1198 ◽  
Author(s):  
P. J. Garlick ◽  
M. A. McNurlan ◽  
P. E. Ballmer
Keyword(s):  
Dietary Protein ◽  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Dietary Protein Intake ◽  
Body Protein

scholarly journals Effects of long-term protein excess or deficiency on whole-body protein turnover in sheep nourished by intragastric infusion of nutrients

1995 ◽  
Vol 73 (6) ◽  
pp. 829-839 ◽  
Author(s):  
S. M. Liu ◽  
G. E. Lobley ◽  
N. A. Macleod ◽  
D. J. Kyle ◽  
X.B. Chen ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Protein Turnover ◽  
Protein Intake ◽  
Volatile Fatty Acids ◽  
Whole Body ◽  
N Losses ◽  
Body Protein ◽  
Fractional Rate ◽  
The Difference

The effect of long-term dietary protein excess and deficit on whole-body protein-N turnover (WBPNT) was examined in lambs nourished by intragastric infusions of nutrients. Ten sheep were given 500 mg N/kg metabolic weight (W0.75) per d from casein for 2 weeks and then either 50 (L), 500 (M) or 1500 (H) mg N/kgW0.75per d for 6 weeks. Volatile fatty acids were infused at 500 kJ/kgW0.75per d. Daily WBPNT was measured by continuous intravenous infusion of [l-13C]leucine 3 d before, and on days 2, 21 and 42 after the alteration in protein intake. Whole-body protein-N synthesis (WBPNS) was calculated as the difference between WBPNT and the protein-N losses as urinary NH3and urea. Whole-body protein-N degradation (WBPNS) was then estimated from WBPNS minus protein gain determined from N balance. Fractional rates of WBPNS and WBPND were calculated against fleece-free body N content. WBPNS rates at the L, M and H intakes were respectively 35·1, 41·5 amd 6·37 g/d (P< 0.001) on average over the 6 weeks and WBPND rates were 39·5, 41·1 and 56·8 g/d (P< 0.001). The fractional rates of WBPNS were 5·01, 6·37 and 7·73% per d (P< 0.001) while those of WBPND were 5·64, 6·29 and 6·81% per d (P< 0.005) respectively. On days 2, 21 and 42, WBPNS rates at intake H were 54·0, 61·8 and 75·4 g/d (P= 0·03) respectively, and WBPND rates were 43·2, 56·4 and 70·9 g/d (P= 0.03); at intake L the amounts were 38·2, 34·2 and 32·8 g/d for WBPNS (P= 0.003) and for WBPND were 43·4, 38·0 and 36·9 g/d (P= 0·016) respectively. There were no significant (P> 0·05) differences in fractional rates of WBPNS and WBPND with time at either the L or H intake. We concluded that absolute protein turnover was affected both by dietary protein intake and by body condition while the fractional rate of turnover was predominantly influenced by intake.

scholarly journals Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males

2012 ◽  
Vol 9 (1) ◽  
pp. 91 ◽  
Author(s):  
Daniel R Moore ◽  
Jose Areta ◽  
Vernon G Coffey ◽  
Trent Stellingwerff ◽  
Stuart M Phillips ◽  
...  
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Body Protein ◽  
Post Exercise

Postexercise Whole-Body Protein Turnover Response to Three Levels of Protein Intake

2007 ◽  
Vol 39 (3) ◽  
pp. 480-486 ◽  
Author(s):  
PATRICIA COURTNEY GAINE ◽  
MATTHEW A. PIKOSKY ◽  
DOUGLAS R. BOLSTER ◽  
WILLIAM F. MARTIN ◽  
CARL M. MARESH ◽  
...  
Keyword(s):  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Body Protein

Nitrogen Homoeostasis in man: The Diurnal Responses of Protein Synthesis and Degradation and Amino Acid Oxidation to Diets with Increasing Protein Intakes

1994 ◽  
Vol 86 (1) ◽  
pp. 103-118 ◽  
Author(s):  
Paul J. Pacy ◽  
Gill M. Price ◽  
David Halliday ◽  
Marcello R. Quevedo ◽  
D. Joe Millward
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Dietary Protein ◽  
Protein Turnover ◽  
Protein Intake ◽  
Whole Body ◽  
Body Protein ◽  
Fed State ◽  
Leucine Kinetics ◽  
Synthesis And Degradation

1. The diurnal changes in whole body protein turnover associated with the increasing fasting body nitrogen (N) losses and feeding gains with increasing protein intake were investigated in normal adults. [13C]Leucine, [2H5]phenylalanine and [2H2]tyrosine kinetics, were measured during an 8h primed, continuous infusion during the fasting and feeding phase together with fed-state N turnover assessed with [15N]glycine after 12 days of adaptation to diets containing 0.36 (LP), 0.77 (MP), 1.59 (GP) and 2.07 (HP) g of protein day−1 kg−1. Measurements were also made of fasting and fed resting metabolic rate and plasma hormone levels. 2. Resting metabolic rate in the fasted and fed state was not influenced by dietary protein intake, but was increased by feeding (11-13%, P <0.01) with no influence of dietary protein concentration. Fasting plasma insulin levels were not influenced by protein intake and were increased by feeding independent of protein intake. Fasted but not fed values of insulinlike growth factor-1 increased with protein intake, although no feeding response was observed. Thyroid hormones (free and total tri-iodothyronine) did not change in any state. 3. For leucine with increasing protein intake the increasing fasting losses reflected increasing rates of protein degradation, although the changes were small and only significant between GP and MP intakes. The increasing leucine gain on feeding was associated with increasing rates of protein synthesis and falling rates of protein degradation, reflecting a progressive inhibition of degradation with feeding, and a change from inhibition of synthesis (LP diet) to stimulation (GP and HP diets). Mean daily rates of synthesis and degradation did not change with protein intake. 4. Phenylalanine and tyrosine kinetics were calculated from adjusted values based on leucine kinetics and published data of the hepatic/plasma enrichment ratio. With the increased protein intake, the increasing fasting losses of phenylalanine (GP > MP) were mediated by increasing rates of degradation (paired t-tests). The increasing phenylalanine gain (GP > MP > LP) was due to increasing fed-state rates of synthesis and falling rates of degradation, reflecting a progressive inhibition of degradation, a stimulation of hydroxylation and a variable response of synthesis ranging from inhibition at the lowest intake to stimulation at higher intakes. For tyrosine a similar progressive inhibition of degradation with intake was shown. Mean daily rates of synthesis and degradation (phenylalanine) and degradation (tyrosine) did not change with protein intake. 5. Estimation of protein turnover from 15N excretion in urea and ammonia during 9 h after 1 h intravenous infusion of [15N]glycine in the fed state on the LP, MP and GP diets indicated that neither synthesis nor degradation were influenced by dietary protein level. Synthesis estimated from 15N kinetics was significantly correlated with that determined from leucine kinetics (r = 0.78, n = 14, P <0.01) and from phenylalanine kinetics (r = 0.53, n = 14, P <0.05), and degradation estimated from 15N kinetics was significantly correlated with that determined from leucine kinetics (r = 0.60, n = 14, P <0.05). Thus the [15N]glycine, [13C]leucine and [2H5]phenylalanine methods gave broadly comparable results. 6. We conclude that the feeding response of protein synthesis, degradation and amino acid oxidation reflects the combined impact of insulin and tissue amino acid levels with insulin inhibiting degradation and with amino acids both stimulating synthesis and oxidation and also further inhibiting degradation. Although the dietary protein level influences the extent of these feeding responses, it does not influence the mean daily rate of protein turnover. The rate of whole body protein turnover per se is unlikely to provide an indicator of protein nutritional status.

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