Obesity rates in the United Kingdom are fast catching up with those in the United States, with 24 percent of women and 20 percent of men now considered obese, according to researchers at Cancer Research UK.

A further 50 per cent of British men and 33 percent of British women are overweight, the researchers added.

The researchers warned that the increase in obesity in the United Kingdom is creating a cancer timebomb, since the risk of developing cancer is up to five times higher for overweight people.

"We are getting fatter and it is causing cancer," said Professor Julian Peto of the Institute of Cancer Research. "'British men are now where American men were six years ago. There's such a huge prevalence of obesity and it's causing ill-effects in people's health."

"Being overweight is the most avoidable cause of cancer in non-smokers," Peto said.

He said obese men, with a body mass index (BMI) of 30 to 35, are at nearly double the risk of cancer of the liver and esophagus, 50 per cent more likely to get colorectal cancer, and 20 per cent more likely to develop prostate cancer.

Among very obese men, with a BMI of 35 and over, the risk of liver cancer rises more than threefold, while there is an 80 per cent extra risk of colorectal cancer, and a 30 per cent increased risk of prostate cancer, Peto added.

Obese women are 60 per cent more likely to have breast cancer and run more than double the risk of cancer of the womb and esophagus, he said.

Women with a BMI of 35 and over are twice as likely to develop lymphatic cancer, more than three times as likely to develop cancer of the cervix and almost three times as likely to have cancer of the womb.

Other sources: Cancer Research UK, Daily Mail