Arne Astrup, who conducted the study, told the BBC the drug mimics the behavior of a natural hormone called GLP-1, which is released by the small intestine after you eat. The hormone tells the brain you're full and the body to produce digestive insulin, but the effect dissipates quickly.
The drug allows your body to feel the effects of GLP-1 for a full 24 hours, making it resistant to the body's natural self-destruct mechanism.
Critics will note that this is an injected drug, while Xenical is a tablet. Some are also questioning its use in weight loss.