Calcium, Protein and Gut Hormones

Participants will be asked to arrive to the laboratory between 08:00 and 10:00 am after not eating for between 8-14 hours i.e. in a fasted state (water intake is permitted and encouraged). Participants will then be given one of three test drinks: 1) calcium citrate (1000 mg); 2) milk mineral supplement (equating to 1000 mg calcium); or 3) milk mineral supplement (equating to 1000 mg calcium) plus whey protein hydrolysate (50 g). Each of these drinks will also contain 500 mL of water and artificial sweetener (80 mg sucralose).

Blood samples will be taken before, and at 15, 30, 45, 60, 90 and 120 minutes after ingestion of the test drink to determine the concentrations of gut hormones (GIP, GLP-1 and PYY) circulating in the bloodstream. We will also ask participants to complete an appetite questionnaire at baseline and every 30 minutes after ingestion of the test drink to assess their appetite sensations. After the 120-minute time point, we will remove the cannula and the trial day will be complete.

Inclusion criteria

• Healthy men and women age between 18-65 yrs.
• Able to consume provided supplement.
• Weigh stable for the past 3 month (no change within 3%).

Exclusion criteria

• Any previous or current metabolic, cardio-pulmonary or musculoskeletal disease
• Not between the ages of 18-65 years
• A body mass index below 18.5 kg/m2 or above 30 kg/m2 (body mass (kg) divided by your height (m) squared)
• Taking medications that may influence your metabolism
• Plans to change your lifestyle (diet and/or physical activity) during the study period
• Not willing to refrain from alcohol containing drinks or unaccustomed exercise one day before the laboratory sessions.
• Current smoker