Lactose, one of the key nutrients in human milk may be critically important to infants for more reasons than being a source of energy. We are interested in understanding how lactose when compared to other sugars influences how nutrients, specifically macronutrients are handled after digestion and absorption. To date, there have been no studies looking at how fat and protein varies when lactose compared to other sugars is ingested. There may be metabolic advantages to considering lactose for nutrition support of premature infants rather than glucose or dextrose as is often used in intravenous feeds, or the corn syrup solids in lactose-free formulas. We hope the information from this study will provide new information on the unique aspects of lactose.

Hypothesis: The hypothesis is that providing carbohydrate as lactose:

1. minimizes the amount of carbohydrate that is converted into fat
2. enables a relatively constant metabolic state throughout feeding interval that avoids swings of high to low insulin, glucose, and fats.

Inclusion Criteria:

• male
• at least 19 years of age
• body mass index (BMI) between 18.5 and 25
• fasting blood glucose level < 6.1 mmol/L (110 mg/dL) measured by glucometer on the day of the study and
• comfortable speaking, reading and understanding English
• comfortable drinking at least one cup (250 ml) of milk
• non-smoking

Exclusion Criteria:

• not willing to provide blood samples, have
• impaired lactose or glucose tolerance,
• pre-diabetes, diabetes mellitus and any other endocrine disorder,
• coronary heart disease, liver function test abnormalities or any chronic disease
• routinely take medications, including aspirin, cyclooxygenase-2 inhibitors, statins and fish oil
• consuming more than 1 alcoholic drink per day