Evidence that transient nicotine lowers the body weight set point.

Objective: Smokers usually gain weight when they quit smoking. The present work explores the hypothesis according to which such a rise is a behavioral response to a raised body weight set point taking place when nicotine is eliminated from the body.

Research Methods And Procedures: The human body weight set point was assessed with classical behavioral and psychophysical methods, from the delay to experience negative alliesthesia when repeatedly ingesting sweet stimuli. Seven habitual smokers were tested once before lunch, after smoking (nonabstinent) as usual and once again after refraining from smoking (abstinent). Three additional nicotine-naive subjects were tested under the same procedure after receiving at 0730 h in the morning a transdermal nicotine patch (14 mg) or a placebo patch. Two of the subjects also received nicotine (7 mg) for a third session.

Results: Oral and transdermal administration of nicotine did not decrease the initial pleasure or modify the initial palatability of eating sweet stimuli, but significantly accelerated the following onset of self-reported displeasure (negative alliesthesia) aroused by repeated ingestion of sweet stimuli.

Discussion: These results are understood as an acute lowering of the body weight set point by nicotine. The body weight gain taking place after quitting smoking may, therefore, be explained by the removal of the lowering of the body weight set point induced by nicotine.