Only 3% of people know they can reduce their risk of getting cancer by maintaining a healthy weight, according to a survey.
Cancer Research UK polled 3,947 people and found that just 11% listed using sunscreen or staying out of the sun as things people could do to boost their chances of avoiding the disease.
Two thirds of those surveyed said stopping smoking could cut their risk of getting cancer and 59% were aware that altering their diet could also help.
Nearly one in three (29%) knew that taking regular exercise could reduce their chances of cancer while 22% listed cutting back on alcohol.
Obesity or being overweight is just behind smoking in being one of the biggest risks in developing cancer.
Figures show that more than 13,000 cases of the disease could be prevented each year in the UK if people maintained a healthy weight.
Some 7% of those polled were unable to list one positive way in which people could help themselves prevent cancer.
Sara Hiom, director of health information at Cancer Research UK, said: "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."