Growing evidence shows that the brain regulates bioenergetic balance by responding to peripheral leptin signals released by fat cells. A new study adds to this evidence by identifying the mechanism by which leptin is transported into the brain and showing that the lack of a functional leptin receptor in hypothalamic tanycytes results in the development of type 2 diabetes and obesity while reinstating the function of this critical receptor reestablishes normal pancreatic insulin secretion and blood glucose levels. The study supports that the brain is critical in fuel homeostasis and leptin transport may provide a new target for therapeutic intervention.