The current study will investigate the effect if whey protein on postprandial glycaemia and appetite in type II diabetics, assessing incretin (GLP-1, GIP), insulin, and appetite control (leptin, PYY3-36) hormone responses.

Whey protein accounts of ~20% of whole milk protein. Ingestion of whey protein at meal times generates insulinotrophic/β-cell stimulation via amino acid absorption and the bioactive peptides generated during gastrointestinal digestion, resulting in attenuation of postprandial blood glucose. The bioactive peptides stimulate the release of incretin hormone, GLP-1, and inhibit DPP-IV activity potentially decreasing the rate of GLP-1 degradation.

The current study will employ a randomised, double-blind, counter-balanced, cross-over design, whereby participants will each complete three trials; a) whey protein, b) hydrolysed protein, and c) placebo intervention. Hydrolysed protein provides amino acid content, without bioactive peptides associated with incretin release, therefore, demonstrating insulinotrophic properties, only.

Many studies within the literature are limited for practical reasons, such as investigating high dosages (30-50 g) of whey protein, or high glycaemic index meal types which would be unlikely to form part of habitual dietary activity of type II diabetics. Therefore, the current study will objectively measure postprandial glycaemic and appetite responses following the ingestion of whey/hydrolysed protein, whilst ensuring ecological validity, dosages (18 g) and test meals applicable to everyday life, and true clinical utility for managing type-II diabetes by integrating interventions into the habitual lives of type-II diabetic individuals.

Inclusion Criteria:

• Type II diabetic males aged 18-65 years old.
• Treated with metformin, or diet and lifestyle modification, only.
• BMI < 40 kg/m2.
• Stable physical activity pattern during the three months immediately preceding study.

Exclusion Criteria:

• Not treated with insulin.
• No metabolic disease other than diabetes.