You can't out-exercise a bad diet... If you can not out-exercise a bad diet, then why try. It's much easier NOT to put that crap into you mouth than it is to have to work for hours to get most of it out of your system. No matter how hard you try, you can not get it all out of your system. Some of that fat is in-jested into your veins and that is what leads to heart attaches and other issues. Also eating those kinds of food can make you not want to work out and become lazy.
Your body is your temple... You need to protect it.