So when studies are done to look at fat intake and the risk of breast cancer, it is hard to know whether you should ask someone about what they are eating now or what they ate when they were children. The other difficult thing is it is hard to get people to accurately report what they are eating. For example, if my mom asks me what I had for breakfast, I will tell her about all the healthy things I ate but might not tell her about the unhealthy stuff. We also don't know when changing diet is most important. Then at the end of five years, the researchers will look to see if this healthy diet helps prevent breast cancer.
Fewer men get breast cancer than women, but men can get breast cancer.
So if a man develops a lump in his breast tissue, then it needs to be checked out. This does not mean that there aren't genes that we inherit that might increase our risk of breast cancer. It may be that we just haven't found them yet. But the biggest risk factor for getting breast cancer is just to be a woman in an industrialized country like the United States. We don't know.