University of Arkansas, Fayetteville Division of Agriculture


Breakfast consumption has been linked to health benefits such as improved weight regulation and glucose control. Studies have shown higher protein breakfasts lead to a greater reduction in hunger compared to breakfasts higher in carbohydrates. However, few studies have examined the impact of higher protein breakfasts from differing protein sources. The objective of this study was to determine if protein quality (animal (AP) versus plant (PP) protein) influences postprandial appetite, food cravings, food intake and glucose response in participants consuming a high protein breakfast (~30% energy from protein). We hypothesized that AP would be more satiating than PP. Normal weight (NW; n = 12) and overweight women (OW; n = 8) ages 18-36 were recruited to participate. All participants completed two visits in a randomized, cross-over design with one week between visits. Blood glucose and appetite were assessed at 0, 15, 30, 45, 60, and 120 min postprandial. Participants kept a 24-h dietary record for the duration of each test day. Participants preferred the appearance of the AP meal compared to the PP (P < 0.05). No difference was found between NW and OW participants or breakfasts for postprandial appetite responses. The AP had a significantly lower (P < 0.05) glucose response at 30 min compared with PP (-11.6%; 127 + 4 versus 112 + 4 mg/dL) and a slower return to baseline. There was no significant difference in daily energy intake between breakfasts. These data suggest protein source influences postprandial glucose response without significantly impacting appetite response and food intake in regular breakfast consumers.