Smokers often do gain weight when they quit, but is smoking itself an aid to weight control? We asked Dr. Arthur Frank, medical director of the weight-management program at George Washington University Hospital. His response: "Anyone who smokes simply as a method of weight control is a fool. As dangerous as it is to be overweight, using tobacco for weight control is a suicide gesture."

Frank says that former smokers sometimes resume smoking in hopes of losing weight they gained when they quit--and they're usually disappointed. In these cases, it's often the hand-to-mouth fixation that people are looking to satisfy.

Frank concedes that smoking "probably does increase metabolism slightly"--chiefly from the nicotine but also from the poisonous effect smoking has on metabolic enzymes. But any benefit is far outweighed by smoking's deleterious effects, he says.