The obesity epidemic in Britain could lead the number of people with cancer to double in the next 40 years, an expert has warned.
Professor Martin Wiseman, medical and scientific adviser at the World Cancer Research Fund (WCRF), said that after not smoking, maintaining a healthy weight is the most important thing a person can do to prevent cancer.
Speaking ahead of a conference organised by the charity and the Association for the Study of Obesity (ASO), Professor Wiseman said figures suggest a third of women and half of men will be obese in the next 40 years.
"Unless something happens soon to stop the increase in obesity then we are sleepwalking towards a situation where the UK will be facing more cancer cases than ever before," he said.
"Rising obesity rates are not the only reason we expect the number of cancer cases to double over the next 40 years, but it is an important factor."
Professor John Wilding, chairman of the ASO, added: "This is an extremely important subject because there is convincing evidence that excess body fat is a cause of several types of cancer.
Excess body fat is linked to cancer of the bowel, breast, womb, oesophagus, kidney and pancreas.