Effects of nicotine on hunger and eating in male and female smokers

We tested whether the inverse relationship between smoking and body weight may be due in part to nicotine's acute effects on reducing hunger and eating. On four mornings, male and female smokers (n=10 each), abstinent overnight from smoking and food, received one of three nicotine doses (7.5, 15, and 30 μg/kg) or placebo (0) via nasal spray every 30 min for 2 h. Self-reported hunger and satiety ("fullness") and craving for cigarettes were obtained after each dose presentation. Subjects subsequently ate ad lib from a large array of food items varying in sweet taste and fat content. For both males and females, nicotine had no effect on self-reported hunger, but cigarette craving was decreased. Rather than being decreased, caloric intake during the meal was unexpectedly increased following nicotine compared with placebo. Cigarette craving increased after the meal, and this increase was unaffected by nicotine dose. There were virtually no differences between males and females in any effects of nicotine. These results indicate that nicotine may not acutely suppress appetite in fasting smokers and suggest that other actions of nicotine or smoking may account for the lower body weights of smokers.