OpenSOurce Diets- www.ResearchDiets.com
J. Nutr. First published March 24, 2010; doi:10.3945/jn.109.120139
 Journal of Nutrition, doi:10.3945/jn.109.120139
Vol. 140, No. 5, 939-945, May 2010
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
140/5/939    most recent
jn.109.120139v1
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Google Scholar
Right arrow Articles by Stepien, M.
Right arrow Articles by Even, P.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stepien, M.
Right arrow Articles by Even, P.
© 2010 American Society for Nutrition

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Postprandial Nutrient Partitioning but Not Energy Expenditure Is Modified in Growing Rats during Adaptation to a High-Protein Diet1,2

Magdalena Stepien, Claire Gaudichon*, Dalila Azzout-Marniche, Gilles Fromentin, Daniel Tomé and Patrick Even

INRA, AgroParisTech, UMR914 Nutrition Physiology and Ingestive Behavior, F-75005 Paris, France

It has been suggested that high-protein (HP) diets may favor weight management by lowering energy intake and reducing body fat. Whether these effects result from changes in energy metabolism remains unclear. We measured the adaptation of energy metabolism components during 2 wk of HP feeding. Fifty male Wistar rats were switched from a control diet to an HP diet (14 and 55% of protein, respectively) for 1, 3, 6, or 14 d. Energy expenditure (EE) and substrate oxidation were measured by indirect calorimetry in feed-deprived rats and after consumption of a test meal. EE components, including the thermic effect of feeding and activity, were not modified during adaptation to an HP diet. Nutrient oxidation in feed-deprived rats was not affected by HP feeding, except for an early increase in protein oxidation. After 1 d, the postprandial inhibition of lipid oxidation (Lox) was blunted, carbohydrate (CHO) oxidation decreased by one-half, and urea clearance decreased by 66%. Thereafter, CHO oxidation gradually rose, resulting in a null CHO balance. Lox and urea clearance recovered after 3 d of adaptation to an HP diet, while protein oxidation reached a plateau. The postprandial oxidation of CHO counterbalanced the amount of ingested CHO as soon as 3 d, leading to a null postprandial CHO balance. We conclude that the inhibition of de novo lipogenesis from dietary CHO, but not EE and Lox, may participate in limiting the adiposity induced by HP feeding. The transient changes occurring during the period of adaptation to the diet highlight that the duration of the diet is critical in HP diet studies.

* To whom correspondence should be addressed. E-mail: claire.gaudichon{at}agroparistech.fr.

Manuscript received 16 December 2009. Initial review completed 7 January 2010. Revision accepted 4 March 2010.

Published online 24 March 2010.