The subject will be randomly allocated to receive one of the three study drinks. At 7:50am baseline blood will be sampled (10ml [1.5 tablespoons] via the drip needle). At 8am the volunteers will drink the study drink. The rate of stomach emptying will be measured by using Gamma scintigraphy (a specialised medical camera). The drinks will have added a tracer substance that is visible on the camera and allows us to follow drink as it passes through the stomach into the bowels. Each 'picture' of the stomach lasts 20 seconds and we plan to take these every 20 minutes for 4 hours after intake of the drink. At 20 minute intervals (until 220 mins have elapsed) 7ml (1 tablespoon) of blood will be sampled via the drip needle. The final 10 ml blood sample will be taken at 240 minutes following which the drip needle will be removed and the volunteers will be allowed home. The subsequent two studies will be performed 7 days following the first study.