Ninety-seven per cent of people don’t list being overweight as a cancer risk, according to a Cancer Research UK survey out today.

After smoking, being overweight or obese is one of the biggest cancer risks.

But in a survey of nearly 4,000 people, only three per cent mentioned keeping a healthy bodyweight as something people could do to reduce their risk of cancer.

And seven per cent of those surveyed failed to name a single positive change people could make to help to prevent the disease.

Sara Hiom, director of health information at Cancer Research UK, said: “Encouraging people to change their behaviour is often difficult, but the first step is to build awareness that these changes are worth making.

“We have estimated that more than 13,000 cases of cancer could be prevented each year if everyone maintained a healthy weight.

“While many people may associate weight with being healthy in general, this survey shows that most people don’t link it directly with their risk of cancer, or don’t know how much it can reduce their risk.”

Two thirds of people surveyed mentioned giving up smoking as a way to reduce cancer risk.

Fifty-nine per cent of people said that food and diet was important, and 29 per cent understood that exercising more would help.

Twenty-two per cent of people, unprompted, said alcohol influences our risk of the disease, and 11 per cent said they knew that protecting your skin in the sun was important.

Sara Hiom added: “It may be hard for people to make the link between obesity and an increased risk of cancer because we generally associate having the disease with being underweight. But carrying extra weight means producing more chemicals in our bodies that can cause cancer to develop.

“We know it can be hard to make long-lasting changes to our lifestyles, like quitting smoking and cutting down on alcohol. But it’s important that people are aware of the things that they can do – and the extent to which these changes will affect their cancer risk – so that they can make informed choices.

“Leading a healthy life with a balanced diet and plenty of exercise does not guarantee that a person won’t get cancer but these healthy habits can help to cut the odds.”

The survey was carried out face-to-face during October 2008 by the British Market Research Bureau for Cancer Research UK.

3,947 people were asked: “What are the main changes people can make to their lifestyles to reduce the risk of cancer?” Participants, who were not given a list of options to choose from, named the below factors in response.

Smoking = 66%
Food and diet = 59%
Exercise = 29%
Alcohol = 22%
Sun and skincare = 11%
Bodyweight = 3%
Don’t know / nothing = 7%

About a third (31%) of people mentioned 3 or more of the above lifestyle changes.