The Impact of Phosphate Bioavailability on the Hormonal Response to a Breakfast Meal in Healthy Humans

In the first meal, the participant will consume a standard convenience breakfast meal comprised of a cheese tea biscuit and two Eggo waffles. The amount of phosphorus contained in this meal is 700 mg and the majority of this phosphate would be in the form of phosphate additives. Urine and blood will be collected before and after consumption of the meal to measure how the body responds to the meal. Specifically, levels of phosphate, calcium, creatinine (measure of kidney function) and three hormones involved in phosphate regulation (parathyroid hormone, fibroblast growth factor-23 and vitamin D) will be measured in each blood sample. Creatinine, calcium and phosphate will be measured in each urine sample. The second meal will also contain 700 mg of phosphorus and similar caloric content but in a healthy breakfast meal that does not contain any phosphate additives, consisting of one cup of All-Bran breakfast cereal with milk and a piece of fruit. The same blood and urine tests will be assessed after the second meal.