QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hartsook, E. W. Articles by Nee, J. C. M. Search for Related Content PubMed PubMed Citation Articles by Hartsook, E. W. Articles by Nee, J. C. M.

Effects of Dietary Protein Content and Ratio of Fat to Carbohydrate Calories on Energy Metabolism and Body Composition of Growing Rats¹

Nutritional Laboratories, Department of Animal Science, The Pennsylvania State University, University Park, Pennsylvania 16802

Relationships among dietary protein, fat and carbohydrate were investigated in a modeling experiment using male rats and isocaloric diets factorially arranged to describe outcome responses of diets varying in protein content from 6 to 70% and in fat to carbohydrate calories ("ratio") from 0.2 to 1.4. Regression of body weight, weight gain and carcass dry matter, nitrogen and ash gain on protein and "ratio" was described by linear and quadratic coefficients for protein. Energy gain was optimal at 37.3% protein, Maximum quantities of heat of basal metabolism occurred at a dietary composition of 38.5% protein, 42.6% carbohydrate and 12.9% fat. Fecal and urinary nitrogen increased as dietary protein increased, but decreased as "ratio" increased. Body nitrogen gain, unaffected by "ratio," was maximal at 44% dietary protein. Digested energy and metabolized energy were unaffected by "ratio" at 40% protein, but at low and high protein, the effect of "ratio" was negative and positive, respectively. Heat production was constant at a "ratio" of 1.4; below and above 36% protein it was increased and decreased, respectively, by lower "ratios." Heat increment, unaffected by "ratio," was minimal at 46% dietary protein. Significance of this model to human and animal nutrition is discussed.

KEY WORDS: • energy • protein • nitrogen • fat • carbohydrate

¹ Authorized for publication January 12, 1971 as Journal Series no. 8909.

Manuscript received 6 May 1971.

This article has been cited by other articles:

				O. A. Olukosi and O. Adeola Estimation of the metabolizable energy content of meat and bone meal for swine J Anim Sci, August 1, 2009; 87(8): 2590 - 2599. [Abstract] [Full Text] [PDF]

				K.-H. Kim, L. Zhao, Y. Moon, C. Kang, and H. S. Sul Dominant inhibitory adipocyte-specific secretory factor (ADSF)/resistin enhances adipogenesis and improves insulin sensitivity PNAS, April 27, 2004; 101(17): 6780 - 6785. [Abstract] [Full Text] [PDF]