Meal consisting of egg white protein yields higher satiety than an isocaloric wheat gluten protein meal

Abstract

Satiety is a primary factor influencing total food intake and high protein diets may produce greater satiation. We examined whether the composition of “breakfast” (BF), the first meal following an overnight fast, influenced the timing and size of a subsequent meal. Young‐adult male Sprague‐Dawley rats (n=24) were entrained to a meal‐feeding schedule which included an overnight fast (no food during light period and first hour of dark cycle) before being provided BF. For BF, rats were allowed 30 minutes to consume 20% of average daily intake of one of three isocaloric diets. The basal diet was 60:20:20 (carbohydrate:protein:fat, as a % calories) with protein being provided equally by egg white protein (EW) and wheat gluten protein (WG). The two remaining diets were 45:35:20 with protein provided by either EW or WG. In the first study, rats had access to basal diet 15 min after BF. Rats fed WG consumed more (p<0.01) than rats fed either basal or EW (6.8 ± 1.0 vs 4.8 ± 0.6 and 2.9 ± 0.4, respectively). In study two, to test for dietary preference, rats were randomly assigned to freely choose between two of the three diets for 90 min immediate following BF. The study was repeated until all rats experienced all 3 diet pairings. Across all choices, rats fed WG consumed more (p<0.01) than basal‐fed rats (6.3 ± 0.6 vs 4.7 ± 0.3) while EW‐fed rats consumed less (p<0.05; 3.2 ± 0.3). Animals consumed less (P < 0.01) of the EW diet regardless of breakfast type. These results indicate that the satiation from high protein diets is dependent upon the protein source. Egg white protein was more satiating than wheat gluten.Grant Funding Source: NIH and various donors