Researchers found quitters had a 70% increased risk of developing type-two diabetes in the first six years without cigarettes compared with non-smokers.
This is because they tend to put on weight.
However, the Annals of Internal Medicine study stressed that this should not be used as an excuse to carry on smoking.
On no account should people use the theoretical results of this study as an excuse not to give up smoking
The Johns Hopkins team also stress that smoking is a well known risk factor for type-two diabetes – as well as many other health problems, such as heart disease, stroke and cancer.