Metabolic Consequences of Egg White versus Wheat Gluten Protein Consumption in a Rodent Model

Abstract

High-protein diets are popular for weight management because of their ability to enhance satiety but not all protein sources are similarly anorexigenic. We recently reported that egg white protein is more satiating than wheat gluten in Sprague Dawley rats. The goal of this study was to identify physiological correlates of the satiety differences and to test long-term consequences on metabolism, body composition and body weight. At both 20% and 35% levels, egg white increased total plasma amino acids relative to wheat gluten. Insulin levels were unaffected but respiratory exchange ratio was reduced for several hours following 35% egg white relative to the other diets. No chronic effects on body weight, body composition, energy intake, or energy expenditure were observed. Results suggest that increased satiety-signaling amino acids may underlie greater short-term satiety from egg white, but when consumed only once per day, produces no long term consequences for body composition.