British researchers have confirmed that being overweight doubles the risk of certain cancers in women.

Being overweight or obese accounts for one in 20 cancer cases diagnosed in women in their 50s and early 60s each year, researchers from Oxford University said in a study published Wednesday in the British Medical Journal.

"We estimate that being overweight or obese accounts for around 6,000 out of a total 120,000 new cases of cancer each year among middle-aged and older women in the UK," lead researcher of the study Gillian Reeves said.

According to the study, half of the 6,000 cases of endometrial cancer (cancer of the womb) diagnosed in Britain each year are caused by the patient being overweight or obese.

"Our research also shows that being overweight has a much bigger impact on the risk of some cancers than others. Two thirds of the additional 6,000 cancers each year due to being overweight or obesity would be cancers of the womb or breast," she added.

Excess weight is also a major risk factor in one kind of oesophageal cancer (cancer of the throat).

Obesity is also found to increase the risk of kidney cancer, leukemia, multiple myeloma, pancreatic cancer, non-Hodgkin's lymphoma, ovarian cancer and, in some age groups, breast and bowel cancer, the study said.

The researchers have warned that the obesity epidemic is set to worsen with over half of adults and a quarter of children predicted to be overweight by 2050.

Increasing body mass index, a measure of body fat based on height and weight, is associated with an increase in all cancers combined and for 10 out of the 17 specific types of cancer examined.

The risk of developing any cancer is almost tripled with a 10-point rise in body mass index, the study said.

As Britain's largest study on the link between weight and malignant diseases, the study followed more than a million women aging between 50 and 64 for five years.