The study will consist of four occasions with one week between the occasions. fMRI will be performed to monitor hypothalamic activity before and after an ingestion of 1 of the following 4 stimuli (300 ml of each): water at room temperature, water at 0 degrees Celsius, glucose solution at room temperature, glucose solution at 0 degrees Celsius. The last two stimuli both contain 75 gram glucose. The order of conditions will be randomly assigned to the subjects. Functional connectivity of the hypothalamic regions will be assessed by analysing the resting state fMRI.