Weight gain as adult increases cancer risk by up to five times, research shows

A patient inside a CT scanner. The Swedish study found that increased cancer risk was associated with heavier initial weight in early adulthood as well as weight gained during adulthood. Photograph: Sergio Azenha/Alamy

Gaining weight as an adult increases the risk of cancer by up to five times, according to research involving more than 600,000 patients.

Obesity can cause 13 different cancers and is thought to be linked to another eight. But less is known about the impact on cancer risk of the amount of weight put on – and when in life it is gained.