It isn't easy to manage what your diet consists of. Anybody who'se tried to lose (or gain) weight can tell you that. But it's a primary factor in the length and quality of your whole life. Think about that, your entire life. Worth making an effort. It can directly save you from eventual heart disease, and, it turns out, cancer. Those two account for over half the disease deaths in the United States. Think about that, you will live much longer if you eat right. Why aren't all of us intensely studying this subject? I need to learn more.
Here is a good place to start. Take a look at how changing your diet can prevent cancer in an almost sure-fire way. Fascinating.