The Cancer Research U.K. report said tobacco is the biggest culprit in the more than 130,00 cases each year, causing 23 percent of cases in men and 15.6 percent in women, the BBC reported.
The second-leading cause for men is a lack of fresh fruit and vegetables in diets, while for women it is being overweight, the study published in the British Journal of Cancer said.
"Many people believe cancer is down to fate or 'in the genes' and that it is the luck of the draw whether they get it," lead study author Max Parkin said. "Looking at all the evidence, it's clear that around 40 percent of all cancers are caused by things we mostly have the power to change.
"We didn't expect to find that eating fruit and vegetables would prove to be so important in protecting men against cancer," Parkin said. "And among women we didn't expect being overweight to be more of a risk factor than alcohol."
The report added to the "now overwhelmingly strong evidence that our cancer risk is affected by our lifestyles," Rachel Thompson of the World Cancer Research Fund said.