Modified Whey Protein and Effect on Post Meal Glucose Levels Study

After meals, the level of glucose rises in the circulation. In some individuals who are overweight and older, blood glucose can rise to levels which can damage tissues and cause health problems. Usually the hormone insulin, released from the pancreas, effectively lowers blood glucose. However, in overweight and older people insulin is less effective. Certain foods can lower the rise in blood glucose, particularly proteins. This works by increasing the release of a hormone from the gut called Glucagon-Like Peptide 1 (GLP-1), which in turn increases the release of insulin. A Component of milk left over after cheese making, termed Whey protein, is particularly good at releasing GLP-1. Whey protein is used as a food additive and taken as a supplement to help build muscle. Whey protein is a mixture of proteins which the investigators have modified to be more effective at lowering blood glucose. Using laboratory tests the investigators identified a protein present in Whey that does not increase levels of GLP-1 and removed it. It's removal raises the levels of other proteins which are more effective. In this study, the investigators would like to test the effectiveness of the "modified" whey protein. To do this, 30 older, overweight volunteers will be recruited and given the modified whey protein, a normal whey protein or a mixture of amino acids and then a breakfast meal to raise their blood glucose levels. These drinks will be given in a randomised sequence 1 week apart. On each visit, blood samples to measure blood glucose and related hormone levels will be taken. As GLP-1 can also have an effect on appetite, the investigators will measure the effect of the modified whey protein on subsequent appetite in the volunteers by asking them how hungry they feel.

The prevalence of obesity and associated type 2 diabetes has risen dramatically, adversely affecting health and life expectancy and increasing health care costs. There is an urgent need to lower the incidence or delay the onset of both conditions by lifestyle-related interventions. Dietary whey protein acts in the gut to release GLP-1 and insulin release, thereby lowering post-meal glucose levels and satiety. Whey protein is a mixture of proteins which the investigators have modified to be potentially more effective at lowering blood glucose. Using laboratory tests, a protein present in whey that does not increase levels of GLP-1 was identified and removed. Its removal raises the levels of other proteins which are more effective. The study will test the effectiveness of the "modified" whey protein. If the modified whey protein is found to be more effective it may be used to minimise the post-meal rise in glucose levels.

Eligibility Criteria:
Inclusion Criteria:

* Healthy men and women aged 55-75years
* Body Mass index range from 25-35 kg/m2
* Blood pressure below 160/90mmHg

Exclusion Criteria:

* Milk or milk protein allergy
* Lactose Intolerance
* Diabetes
* Smoking
* Taking anoretic drugs, steroid medications, medications known to affect gastric motility or any hypoglycaemic agents
* Unsuitable veins for venous blood sampling
* Inability to spell, read and understand the English language