 Experimental protocol and methods: 16 healthy volunteers will participate in this 4-way study. They will attend one morning for each study, with the studies separated by 1 week. Before the test meal, and after that approximately every 15 min for 1 hour and after that approximately every 20 minutes for 1 hour the level of glucose in their blood will be measured using the finger prick method, as diabetics commonly do to monitor their blood sugars. The participants will also be scanned at baseline, immediately after the test meal and then every hour for 2 hours postprandially. Subjects will be scanned on a research dedicated 1.5T MRI scanner. At baseline and every time the subjects provide a blood glucose sample the participants will be asked to rate their feelings of fullness, hunger and appetite on 100mm VAS scales. 