Anti-smoking measures, such as taxes and bans, eventually lead people to eat better and lose weight. That is the central conclusion of research by Luca Savorelli, Francesco Manaresi and Davide Dragone, to be presented at the Royal Economic Society's 2014 annual conference. The three economists overturn the conventional wisdom that kicking the smoking habit is healthy but results in weight gain.

The research examines the impact of tobacco taxes and smoking bans on eating habits in the United States over the period 1998-2008. According to the report:

After the introduction of new anti-smoking policies, average bodyweight increases and the number of smokers decreases. But within two years people adopt a healthier lifestyle and improve their eating habits, which leads to an overall reduction in the average bodyweight of the population.

There is a general improvement in the quality of people's diet and a reduction in the caloric content of foods, with a reduction in body mass index of about 2.5%. This is a behavioural response to an increase of 10 cents on cigarette taxes.

Smoking bans in bar and pubs cause people to eat less, but also to eat less nutritious food; but smoking bans in restaurants cause people to eat more but better quality food.

In the medium run, smoking bans fight obesity by nudging people to improve their eating behaviour.

Co-author Luca Savorelli comments:

'Preventing behaviour that leads to obesity or tobacco smoking is nowadays a priority both for national governments and the World Health Organization. In the United States,the national health system's expenses amount to about$117 billion to fight smoking and $190 billion to fight obesity.'

'Our research shows that quitting smoking can bring benefits on both fronts: not only does it reduce the risk of pulmonary, heart and cancer related diseases, but it also improves eating behaviour, leading to an increase in physical wellbeing.'

"Tobacco Taxes and Smoking Bans Impact Differently on Obesity and Eating" by Luca Savorelli, Francesco Manaresi and Davide Dragone.