The effect of smoking on appetite is well known to smokers. Individuals who quit smoking gain on average 11–15 pounds in the first 2 years of abstinence, and adolescent girls, in particular, may smoke to control their weight (Stice and Shaw, 2003). As we know well from warnings of public health organizations, there is also a growing obesity epidemic in the United States and across the developed world. Unfortunately, the increase in obesity comes at a time that smoking has declined somewhat, and the New England Journal of Medicine has suggested that the increase in obesity is likely to offset any gains in life expectancy from decreases in smoking (Stewart et al, 2009). Thus, understanding the mechanisms through which smoking decreases appetite could be important in developing novel treatments for individuals who resist quitting for the fear of gaining weight.