Obesity is booming, yet there are only two medications approved for long-term weight loss. Why is it so hard to make a diet pill that works? For one thing, evolution hates diets
As magic little pills go, the weight-loss drug rimonabant was destined to be huge. It was supposed to put a dent in the obesity epidemic and help people quit smoking and improve their cholesterol along the way. Pharmaceutical execs expected it to usher in a new class of drugs bigger than cholesterol-controlling statins, like Lipitor, Pfizer’s $1-billion-a-month blockbuster.