Breast cancer is the most common cancer among women, and obese women are up to 60% more likely to develop cancer as compared to healthy-weight women. A new study found that up to a third of breast cancers in Western countries could be avoided if women ate less and exercised more.

This is wonderful news, and has important implications for human health. Will women take the advice to heart and start eating less and exercising more?

Fat chance.

Two-thirds of American adults are overweight—more of them women than men—yet fewer than one-quarter are dieting. In 2004, the Centers for Disease Control found that women eat over 300 more calories a day than they did in 1971. Fewer than one-third of Americans get regular exercise.

Most Americans, including women, are fat and happy. Of course everyone would love to cut their cancer risk by one-third—unless it means skipping that extra scoop of ice cream, or jogging three times a week. Reducing cancer risk isn’t that important. Until you get it.

As Associated Press reporter Maria Cheng noted, there is a reluctance on the part of many doctors to make too much of this study: “Any discussion of weight and breast cancer is considered sensitive because some may misconstrue that as the medical establishment blaming women for their disease.”

That’s right: there is an institutionalized “fat taboo,” in which some fear that if women (most of whom are overweight) are (truthfully) told that they can reduce their risk of cancer by slimming down will blame themselves if they get cancer. Some activists are also concerned that encouraging overweight women to lose weight will somehow lead to an epidemic of anorexia. The reasoning goes that it may be better to just pretend that there’s nothing women can do to reduce their risk of cancer than to tell them to slim down and get in shape. Of course, this advice cuts both ways: If women (or men, for that matter) are told that they can cut their risk of cancer by as much as a third, it means they are empowered to do something, to take charge of their own health.

No one should be “blamed” for getting a disease, but nor is it a good idea to simply ignore the person’s lifestyle choices that greatly increase their chances of getting that disease. If a person chooses an unhealthy lifestyle (smoking, poor diet, lack of exercise, etc.), doctors should not be shy about warning them the risks they are assuming.

As Cheng noted, some breast cancer groups agree: “Karen Benn, a spokeswoman for Europa Donna, a patient-focused breast cancer group, said it was impossible to ignore the increasingly stronger links between lifestyle and breast cancer. ‘If we know there are healthier choices, we can’t not recommend them just because people might misinterpret the advice and feel guilty,’ she said. ‘If we are going to prevent breast cancer, then this message needs to get out, particularly to younger women.’”

Personally I find the idea that women need to be treated like children insulting; I believe women are smart enough that they can handle the knowledge that they have a significant amount of control over their chances of developing cancer. Knowledge is power, and if, in the process of saving lives, some women get their feelings hurt because they are told to lose weight and get fit (or feel guilty if they don’t), then too bad.