The investigators determined the efficacy of nicotine gum and phenylpropanolamine (PPA) gum relative to a placebo in the reduction of postcessation weight gain throughout a 13-week combined behavioral and pharmacologic treatment program. Following cessation of the drugs at the end of treatment, they monitored long-term effects of these drugs on body weight at both a 6- and a 12-month follow-up. They also determined the mechanism of action of both nicotine gum and PPA gum (viz., changes in dietary intake, physical activity, or metabolic rate) on change in weight during the course of treatment and evaluated withdrawal symptoms of smoking cessation as they were moderated by either nicotine gum or PPA gum use during the course of treatment. Finally, they investigated whether PPA and nicotine gum produced an incremental effect on smoking cessation (relative to placebo gum) in a sample of female smokers who were at high risk for postcessation weight gain at posttest and at a 6- and 12-month follow-up.