Effects of Fluid Milk in Attenuating Hyperglycemia and Hypertriglyceridemia After Meal

Epidemiological studies indicate that risk of type 2 diabetes is lower when milk is consumed in the regular diet. Milk products are unique in that they produce high insulin response despite their low glycemic index. The general aim of the proposed study is to determine the effect of fluid milk on attenuating the postprandial surge in plasma glucose and triglyceride after meals and its associated physiological mechanisms. The investigators hypothesize that the consumption of one or two servings of non-fat milk added to a standard oral glucose tolerance test (OGTT) solution or the high fat tolerance test meal will attenuate postprandial hyperglycemia and triglyceridemia. The investigators hypothesize that the postulated improvement in postprandial metabolic response due to the consumption of fluid milk will be associated with increased postprandial insulin secretion as well as insulin-mediated endothelial vasodilation and whole-limb perfusion.

A double blind randomized placebo-controlled crossover experimental design with six treatments will be used. A total of 30 young (20-40 year old) healthy men and women will serve as subjects. Following 2 days of physical activity and dietary control, subjects will consume a standard OGTT load or high fat tolerance load on the morning of Day 3. The solution used in the meals will be mixed with one or two servings of non-fat milk or placebo (either carbohydrate matched or total calorie matched). Before and after the test meals are consumed, blood samples will be obtained for later analysis of glucose, triglycerides, insulin, and inflammatory cytokines and brachial artery flow-mediated dilation and femoral artery vascular conductance will be measured. The present research project should provide new and clinically useful insight into the role of conventional dairy products on metabolic homeostasis. If the working hypotheses are supported, the information could be used as an initial/preliminary basis for recommendations for the consumption of fluid milk in the prevention of metabolic diseases.

Inclusion Criteria: Apparently health, sedentary. All subjects will have a BMI of 25-35 kg/m2. Exclusion Criteria: Candidates who are taking cardiovascular-acting drugs will not be eligible for participation. Subjects with significant intima-media thickening, plaque formation, characteristics of atherosclerosis, metabolic diseases, gastrointestinal disorders, and/or renal disease will be excluded from the study. Additional exclusion criteria will be cow milk allergy or lactose intolerance, pregnancy or lactation, and alcohol abuse.