Abstract
The correlation of body weight and smoking has been described in many studies. Smokers tend to be on average 3-4 kg lighter compared to non-smokers and are also less likely to be obese or overweight.
Post-cessation weight gain may act as a barrier towards quitting: most quitters gain an average of 3-6 kg within 12 months since smoking cessation, with about a tenth of quitters gaining of more than 10 kg. On the contrary, about 15-20% of smokers lose weight.
The main component of tobacco smoke that leads to weight loss is nicotine. Nicotine reduces weight by reducing appetite and food intake, increasing total and resting energy expenditure, increasing the rate of basal metabolism, and also accelerating lipolysis and fat oxidation.
Weight gain after quitting smoking occurs mainly due to the absence of nicotine effect on the CNS and occurs predominantly within the first three months since cessation. It has also been shown to affect appetite-regulating peptides.
According to the most recent Cochrane review, interventions to influence the post-cessation weight gain with long-term effectivity include individualized weight control programs, exercise programs and nicotine replacement therapy, but no reliable and long-term effective intervention has yet been identified.