American Journal of Clinical Nutrition, Vol 19, 329-334, Copyright © 1966 by The American Society for Clinical Nutrition, Inc.

Influence of Meal Composition on Serum Amino Nitrogen, Glucose and Nonesterified Fatty Acids

¹ From the Agricultural Experiment Station, West Virginia University, Morgantown, West Virginia

Six isocaloric test meals providing two levels of protein and different fat:carbohydrate ratios were administered to ten healthy young men. The amino nitrogen, glucose and nonesterified fatty acid levels in venous blood serum were determined at fasting and at intervals up to 7 hours following the ingestion of the test meals.

The high protein meals produced a significantly greater increase in amino nitrogen concentration than did the moderate protein meals. Serum glucose concentrations, which declined at 1 hours after all meals, were in inverse relation to the amount of protein ingested. Both the amino nitrogen and the glucose responses to the high protein meals were minimized when the meals contained high fat or high carbohydrate calories. A significant negative correlation (–0.84) between serum amino nitrogen and serum glucose concentrations was found at all sampling periods.

In general, nonesterified fatty acid levels decreased before exhibiting a rise following the ingestion of all meals. The nonesterified fatty acid values were directly related to the fat:carbohydrate ratios of the meals. A depressant effect of protein on serum nonesterified fatty acids was evident.