Manipulation of Whey Permeate Formulation for Better Fluid Retention.

The main aim of this clinical trial is to compare the beverage hydration index of three different beverages in primary school-aged children.The Beverage Hydration Index (BHI), compares the hydration value of beverages against water. This study will explore the fluid retention capabilities of strawberry flavoured semi-skimmed milk, a new formulation of whey permeate based on a previous study, and water. This study will also investigate: * Identify the most effective beverage for hydration and the potential cognitive and mood benefits. * To test if these beverages have any effect on gastric emptying * To test if these beverages have any effect on blood glucose. * To test the acceptability and palpability of semi-skimmed milk, whey permeate, and water in primary school-aged children. Participants will: * Take part in three four days (one for each beverage, and a 'low dose' trial, whereby participants will only consume 150ml of the water trial) * Study day will take part between 9:00AM-12:30PM * Participants will also record their food and fluid consumption the day before and consume a standardised breakfast before each trial. * The beverage hydration index will be calculated as the mass of urine collected following control (water) consumption divided by the mass of urine collected following treatment. * Blood and urine samples will be taken to measure hydration * Breath samples will be taken for gastric emptying rate * COMPASS (Computerised Mental Performance Assessment System), fNIRS (Functional Near Infrared Spectroscopy) and visual analogue scales (VAS) measures will be obtained to assess cognition/mood * An ad libitum pasta meal will be consumed after the trial to measure appetite, along with blood glucose and further VAS to measure self reported hunger and fullness. * A focus group will be held following completion of all three beverage trials, to gather participants opinion of each drink.