Journal of Nutrition OpenSOurce Diets- www.ResearchDiets.com

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

Journal of Nutrition Vol. 101 No. 1 January 1971, pp. 61-69
Copyright © 1971 by American Society for Nutrition
This Article
Right arrow Full Text (PDF)
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 arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hussein, M. A.
Right arrow Articles by Scrimshaw, N. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hussein, M. A.
Right arrow Articles by Scrimshaw, N. S.

Daily Fluctuation of Plasma Amino Acid Levels in Adult Men: Effect of Dietary Tryptophan Intake and Distribution of Meals1,2,

Mohammed A. Hussein3, Vernon R. Young, Edwina Murray and Nevin S. Scrimshaw

Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

The daily fluctuations of plasma free amino acid levels were studied under standardized dietary conditions in eight young men. In experiment 1, six subjects were given an otherwise complete diet supplying adequate or no tryptophan for 4 to 7 days as four equal meals at 0800, 1200, 1700 and 2100 hours. In a second experiment, two subjects were given the adequate or tryptophan-free diet for 4 or 5 consecutive days. On the final day of each diet period during experiment 2, each subject received six equal meals at 4-hour intervals, beginning at 0800 hours. With four meals a day the free essential amino acids were generally lowest at 1200 hours and began to rise at this time with peak values being reached between 0400 and 0800 hours. The nonessential amino acids showed less marked and consistent fluctuations during the day. The tryptophan-free diet had little effect on the daily plasma amino acid fluctuations. Feeding six isocaloric, isonitrogenous meals at 4-hour intervals during the 24 hours reduced the evening and early morning rise in plasma essential amino acid levels. It is concluded that the pattern of daily fluctuations in plasma free amino acid levels is significantly affected by the dietary conditions under which the measurements are made.

1 Supported by a Grant no. 12-14-100-9209 (61) from the U. S. Department of Agriculture. These studies utilized the facilities of the M.I.T. Clinical Research Center, supported by U. S. Public Health Service Grant no. FR88.

2 Contribution no. 1662 from the Department of Nutrition and Food Science, Massachusetts Institute of Technology.

3 Present address: Nutrition Institute. Kasr, El-Aini Street, Kasr El-Aini Post Office, Cairo, U.A.R.

Manuscript received 3 June 1970.




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]