To people who have struggled for a lifetime to lose weight, the new drug called rimonabant sounds like a dream come true. It will make a person uninterested in fattening foods, they have heard from news reports and word of mouth. Weight will just melt away, and fat accumulating around the waist and abdomen will be the first to go. And by the way, those who take it will end up with higher levels of H.D.L., the good cholesterol. If they smoke, they will find it easier to quit. If they are heavy drinkers, they will no longer crave alcohol.