…Leptin, the satiety or appetite-suppressant hormone, is secreted by the adipose tissue at levels proportional to the body's fat reserves and regulates appetite by controlling the feeling of fullness. It is transported to the brain by tanycytes—cells which it enters by attaching to the LepR receptors. Tanycytes are therefore leptin's gateway to the brain, helping it to cross the blood-brain barrier and deliver satiety information to the neurons. Previous research has revealed that such transport is impaired in subjects who are obese or overweight. This goes some way to explaining their dysfunctional appetite regulation given that it is more difficult...