|
|
|
|

*
Unité du Métabolisme Protéino-Energétique, Université dAuvergne/Institut National de la Recherche Agronomique, Centre de Recherche en Nutrition Humaine, Clermont-Ferrand, France and
Nestec Ltd., Nestlé Research Center, Lausanne, Switzerland
3To whom correspondence should be addressed. E-mail: boirie{at}clermont.inra.fr.
It has long been recognized that numerous dietary parameters, such as the amount and type of protein and nonprotein energy sources, affect protein metabolism. More recently, we demonstrated that the protein digestion rate is an independent factor regulating postprandial protein gain. Indeed, in young men, using a non-steady-state approach and intrinsically labeled milk protein fractions [whey protein (WP) and casein (CAS)] we showed that a slow digested dietary protein (CAS) induced a greater protein gain than a fast one (WP). The mechanisms of this gain also differed according to the protein rate of digestion. WP stimulated amino acid oxidation and protein synthesis without modifying proteolysis, whereas CAS increased amino acid oxidation and protein synthesis to a lesser extent and strongly inhibited proteolysis. These results led to the concept of "slow" and "fast" protein and were confirmed by further experiments during which the meals tested presented different digestion rates but were otherwise identical in terms of amino acid profile. We also analyzed the effects of fat and carbohydrates added to CAS and WP. Our preliminary results suggest that added nonprotein energy sources to CAS and WP attenuated the differences in both the protein digestion rate and protein gain. Finally, and in contrast to young subjects, a "fast" protein may be more beneficial than a "slow" one in elderly subjects, to limit body protein loss. However, long-term studies are needed to confirm this age-related effect.
KEY WORDS: protein turnover dietary protein digestion non-steady state milk proteins
This article has been cited by other articles:
![]() |
R. Koopman, N. Crombach, A. P Gijsen, S. Walrand, J. Fauquant, A. K Kies, S. Lemosquet, W. H. Saris, Y. Boirie, and L. J. van Loon Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein Am. J. Clinical Nutrition, July 1, 2009; 90(1): 106 - 115. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Koopman and L. J. C. van Loon Aging, exercise, and muscle protein metabolism J Appl Physiol, June 1, 2009; 106(6): 2040 - 2048. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Manders, R. Koopman, M. Beelen, A. P. Gijsen, W. K. Wodzig, W. H. Saris, and L. J. van Loon The Muscle Protein Synthetic Response to Carbohydrate and Protein Ingestion Is Not Impaired in Men with Longstanding Type 2 Diabetes J. Nutr., June 1, 2008; 138(6): 1079 - 1085. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. L. Luhovyy, T. Akhavan, and G. H. Anderson Whey Proteins in the Regulation of Food Intake and Satiety J. Am. Coll. Nutr., December 1, 2007; 26(6): 704S - 712S. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Gaudichon, C. Bos, M. Lacroix, and D. Tome Reply to AH Manninen Am. J. Clinical Nutrition, June 1, 2007; 85(6): 1664 - 1665. [Full Text] [PDF] |
||||
![]() |
T. G. Anthony, B. J. McDaniel, P. Knoll, P. Bunpo, G. L. Paul, and M. A. McNurlan Feeding Meals Containing Soy or Whey Protein after Exercise Stimulates Protein Synthesis and Translation Initiation in the Skeletal Muscle of Male Rats J. Nutr., February 1, 2007; 137(2): 357 - 362. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Lacroix, C. Bos, J. Leonil, G. Airinei, C. Luengo, S. Dare, R. Benamouzig, H. Fouillet, J. Fauquant, D. Tome, et al. Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement. Am. J. Clinical Nutrition, November 1, 2006; 84(5): 1070 - 1079. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. H. Castellanos, M. D. Litchford, and W. W. Campbell Modular Protein Supplements and Their Application to Long-Term Care Nutr Clin Pract, October 1, 2006; 21(5): 485 - 504. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Osowska, T. Duchemann, S. Walrand, A. Paillard, Y. Boirie, L. Cynober, and C. Moinard Citrulline modulates muscle protein metabolism in old malnourished rats Am J Physiol Endocrinol Metab, September 1, 2006; 291(3): E582 - E586. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Phillips, J. W. Hartman, and S. B. Wilkinson Dietary Protein to Support Anabolism with Resistance Exercise in Young Men J. Am. Coll. Nutr., April 1, 2005; 24(2): 134S - 139S. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Prod'homme, M. Balage, E. Debras, M.-C. Farges, S. Kimball, L. Jefferson, and J. Grizard Differential effects of insulin and dietary amino acids on muscle protein synthesis in adult and old rats J. Physiol., February 15, 2005; 563(1): 235 - 248. [Abstract] [Full Text] [PDF] |
||||