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
2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Daniel R. Moore ◽  
Jessica L. Fry ◽  
Meghann J. Robinson ◽  
Joseph W. Hartman ◽  
Stuart M. Phillips

2020 ◽  
Vol 112 (6) ◽  
pp. 1468-1484 ◽  
Author(s):  
Grith Højfeldt ◽  
Jacob Bülow ◽  
Jakob Agergaard ◽  
Ali Asmar ◽  
Peter Schjerling ◽  
...  

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.


1997 ◽  
Vol 127 (9) ◽  
pp. 1788-1794 ◽  
Author(s):  
Daphne L. E. Pannemans ◽  
Anton J. M. Wagenmakers ◽  
Klaas R. Westerterp, ◽  
Gertjan Schaafsma ◽  
Dave Halliday

1989 ◽  
Vol 66 (6) ◽  
pp. 2850-2856 ◽  
Author(s):  
C. N. Meredith ◽  
M. J. Zackin ◽  
W. R. Frontera ◽  
W. J. Evans

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.


2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Megan Colletto ◽  
Jose Rodriguez ◽  
Jeffrey DelFavero ◽  
Nancy Rodriguez

Diabetes Care ◽  
1991 ◽  
Vol 14 (12) ◽  
pp. 1189-1198 ◽  
Author(s):  
P. J. Garlick ◽  
M. A. McNurlan ◽  
P. E. Ballmer

1995 ◽  
Vol 73 (6) ◽  
pp. 829-839 ◽  
Author(s):  
S. M. Liu ◽  
G. E. Lobley ◽  
N. A. Macleod ◽  
D. J. Kyle ◽  
X.B. Chen ◽  
...  

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.


2012 ◽  
Vol 9 (1) ◽  
pp. 91 ◽  
Author(s):  
Daniel R Moore ◽  
Jose Areta ◽  
Vernon G Coffey ◽  
Trent Stellingwerff ◽  
Stuart M Phillips ◽  
...  

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

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