Objectives The purpose of this study was to examine the acute effects of consuming isocaloric, higher-protein breakfast shakes varying in protein source on satiety-stimulating hormone PYY concentrations in healthy adults. Methods Thirty-two adults (Age: 25 ± 1y; BMI: 24.2 ± 0.5 kg/m2) randomly consumed 250 kcal higher-protein breakfast shakes (24 g total protein; 17 g CHO; 9 g fat), varying only in protein source (whey protein isolate, WHEY; soy protein isolate, SOY; Micellar Casein, CAS; pea

more »

... otein isolate, PEA; and milk protein isolate; MILK) for 3 days/shake. On day 4, the participants completed a 4-h testing day that included the consumption of the respective shake followed by blood sampling collected every 30 min to assess plasma Total PYY concentrations. Area under the curve (AUC) analyses were performed. Results Regardless of protein source, the consumption of a breakfast shake led to increases in postprandial PYY concentrations throughout the 4-h period. Although no differences in total (4-h) PYY AUC responses were detected between treatments, PEA elicited greater increases in PYY concentrations during the first 2 postprandial hours compared to MILK and CAS (both, P < 0.05) but not WHEY and SOY. Alternately, CAS elicited greater increases in PYY concentrations during the last 2 hours compared to PEA and SOY (both, P < 0.05) but not WHEY and MILK. Conclusions Regardless of protein source, the consumption of high protein breakfast shakes increased postprandial PYY concentrations in healthy adults. Although total PYY concentrations were not different, the temporal pattern of PYY secretion was influenced by the type of protein consumed. Funding Sources Leprino Foods; Authors' views not official U.S. Army or DoD policy.