Differential Plasma Amino Acid Responses Following the Consumption of Isonitrogenous Doses of Greek Yogurt and Skim Milk

This thesis examined rested postprandial plasma branched-chain amino acid (BCAA) responses after ingesting Greek yogurt (GY) and skim milk (Milk). Utilizing a cross over design, 10 healthy males consumed isonitrogenous boluses of GY and Milk (20 g protein each) at baseline and 60 minutes. Blood was collected at baseline, 30-, 60-, 90-, 120-, 180- and 240-minutes. Leucine, and total BCAA concentrations, maximal concentration (Cmax), time to maximal concentration (Tmax), and total area under the curve (tAUC) were assessed. Significant interactions demonstrated that GY ingestion elicited higher leucine concentration at 60- and 120-minutes and BCAA concentrations at 60-, 90- and 180-minutes vs. Milk. GY exceeded Milk for leucine and BCAA Cmax, with no differences for Tmax. Leucine and BCAA tAUCs were greater for GY vs. Milk. These data demonstrate that GY elicits a greater blood leucine/BCAA response compared to Milk over 4 hours.