Liraglutide in Obesity and Diabetes: Identification of CNS Targets Using fMRI

The main purpose of this study is to help us understand the effects of diabetes medication Liraglutide on weight loss and hunger. The investigators have already determined what the highest tolerated dose of Liraglutide is through earlier human research studies. Liraglutide was approved by the FDA in January 2010 for treatment of diabetes. The investigators will also study the following: 1. The impact of Liraglutide on brain responses to food 2. It\'s effect on physiological and mental performance 3. If its effect on the brain differs among obese and lean diabetic subjects.