Patients with type 2 diabetes who gain weight after quitting smoking still have a lower risk of premature death than those who maintain their weight but continue smoking, a study suggests.

The findings, published in the Lancet Diabetes and Endocrinology, should reassure those with diabetes about the overall health benefits of smoking cessation, the Harvard University-led researchers say.

However, the cardiovascular benefits associated with quitting were only present in those who managed to keep off the extra kilos.

The team analysed data from 20,000 middle-aged and elderly participants from two large prospective US cohorts — the Nurses’ Health Study and the Health Professionals Follow-up Study — to assess the risk of death and cardiovascular disease in relation to weight gain after smoking cessation.