Introduction Smoking prevalence in England has been falling since the 1970s, leading to a substantial reduction in Coronary Heart Disease; but it is now relatively static. At the same time obesity rates have steadily been rising. This is confounded by the fact that giving up smoking has been associated with significant weight gain.

Methods We use methods developed for the English Government Tackling Obesities to predict future trends in obesity and their attendent health problems. We then apply them to future tobacco trends. We then project their impact on future trends in Coronary Heart Disease.

Results Coronary heart disease rates attributable to smoking will continue to decline untill 2020, while the rates attributable to obesity will continue to rise. By 2030 rates of Coronary Heart Disease will begin to rise above current rates as CHD attributable to obesity surpass the gains from smoking reduction.

Conclusion If the rise in obesity is unchecked, any benefits to Coronary Heart Disease rates from smoking reduction will be overtaken in the next 20 years by the growth in obesity. This message needs to understood by policy makers both in England and globally and in particular weight management advice needs to be incorporated into stop smoking services.