I would say that my switch to vegetarianism can fit this question. It was not difficult for me to resist the temptation of eating meat. The difficulty was in finding out how to eat without meat, but more importantly, how to sustain this diet in a society that is meat-crazed and meat-driven. I automatically cannot eat 98& of most restaurant menus simply because almost all of the choices have some kind of meat. In addition, many groceries that you wouldn't think of have meat or were cooked in meat.
It has benefited me greatly. I am now much healthier for it. I lost 10 pounds just by switching over without paying close attention to my diet (I still had snacks). I continued down that road by cutting the crap out of my diet and lost about another 10 pounds. More importantly, however, I am living by what I believe in.