Dairy and Inflammation Study

Following the acquisition of informed consent, eligibility to participate in the study will be determined using questionnaires, and certain parameters determined from a finger-prick blood sample. Eligible participants will be assigned to complete two 6-week dietary interventions in random order, with at least a 4 week "wash out" period (i.e. their habitual eating) in between. The two dietary interventions are: 1) Participants normal, low-dairy diet; and 2) A higher dairy diet where 3 servings per day of dairy foods are provided. Prior to beginning either 6-week diet intervention, participants will be asked to attend the laboratory at York University after an overnight fast to undergo baseline testing.

Following baseline testing, participants will meet with a registered dietitian (RD) to discuss each diet arm. Specifically, if they are on the dairy diet, participants will receive advice on how to incorporate these dairy foods into their diet by replacing other foods of similar energy content so as to not increase their total energy intake and body weight. They will meet with the RD at several other times throughout the study. During each 6-week diet period, they will be asked to keep their physical activity levels constant and to not adopt any other major dietary changes during the study.

At the end of each 6-week intervention period, participants will be asked to return to York University to repeat the initial set of tests performed at baseline. In addition to the fasted tests, a number of tests will be performed after asking participants to consume a high-fat test meal (i.e. a fast-food breakfast). Various measurements will continue to be taken for around 6 hours after this meal is consumed.

Inclusion criteria

• Body mass index (BMI) ≥ 25 kg/m2
• ≤ 2 structured exercise sessions/week
• Habitual low dairy consumption (≤ 1 serving/day)
• Having at least two other metabolic risk factors based on clinical guidelines:

• Elevated blood pressure (≥130/≥85 mm Hg)
• Impaired fasting glucose (≥5.6 mmol/L) measured using a finger prick sample
• Impaired fasting triglycerides (≥1.7 mmol/L) or high-density lipoprotein (<1.03 mmol/L for males, <1.3 mmol/L for females) measured using a finger prick blood sample.
• Increased waist circumference (≥102 cm for males and ≥88 cm for females).
• Borderline high fasting low-density lipoprotein (≥3.5 mmol/L) or total cholesterol (≥5.2 mmol/L).

Exclusion criteria

• Allergy to dairy foods, diagnosed lactose intolerance or an aversion to foods provided during the study
• Previous history of diabetes and/or related cardiovascular disease
• The use of multiple medications for managing lipids, glucose and/or blood pressure