 That's Johan Hari, author of Magic Pill, The Extraordinary Benefits and Disturbing Risks of the New Weight Loss Drugs. The way these drugs work is if you ate something now, it doesn't matter what it is, your pancreas would produce a hormone called GLP-1. And GLP-1 is basically part of your body's natural system going, hey, you had enough, stop eating, right? It's the brakes.