Effects of Dietary Protein and Fiber on Growth and Selected Cholesterol Responses of Rats

Abstract

The effect of dietary protein and fiber on growth and metabolic parameters in blood serum, liver and kidney were determined in a 2 .times. 5 factorial experiment involving 40 Sprague-Dawley rats. Treatment variables were 2 dietary protein levels (16 and 24%) and 5 acid detergent fiber levels (6, 10, 16, 24 and 34%). No difference in growth rate of rats was found due to varying levels of either protein or fiber in the diet. Increasing the dietary protein level from 16-24% resulted in an 18.5% reduction in blood cholesterol. The dietary treatment containing 16% fiber influenced most metabolic parameters examined, including blood serum cholesterol, liver cholesterol and total lipid content in liver and kidney. Rats receiving the diet containing 16% fiber had the highest serum cholesterol (88.9 mg/dl) and the lowest liver cholesterol (4.4 mg/g) as compared with other fiber groups.