Diabetes Care. 2009 Sep;32(9):1600-2. doi: 10.2337/dc09-0723. Epub 2009 Jun 18.

Effects of a protein preload on gastric emptying, glycemia, and gut hormones after a carbohydrate meal in diet-controlled type 2 diabetes.

Ma J1, Stevens JE, Cukier K, Maddox AF, Wishart JM, Jones KL, Clifton PM, Horowitz M, Rayner CK.

OBJECTIVE:
We evaluated whether a whey preload could slow gastric emptying, stimulate incretin hormones, and attenuate postprandial glycemia in type 2 diabetes.

RESEARCH DESIGN AND METHODS:
Eight type 2 diabetic patients ingested 350 ml beef soup 30 min before a potato meal; 55 g whey was added to either the soup (whey preload) or potato (whey in meal) or no whey was given.

RESULTS:
Gastric emptying was slowest after the whey preload (P < 0.0005). The incremental area under the blood glucose curve was less after the whey preload and whey in meal than after no whey (P < 0.005). Plasma glucose-dependent insulinotropic polypeptide, insulin, and cholecystokinin concentrations were higher on both whey days than after no whey, whereas glucagon-like peptide 1 was greatest after the whey preload (P < 0.05).

CONCLUSIONS:
Whey protein consumed before a carbohydrate meal can stimulate insulin and incretin hormone secretion and slow gastric emptying, leading to marked reduction in postprandial glycemia in type 2 diabetes.