In sports when a player isn't working, the coach takes him out. We need to do the same thing in our lives. In the book "Switch" I read about a nutritional experiment where families where asked to change one thing in their diets. They were asked to buy skim milk instead of whole milk. That one switch made a big difference. Participants lost weight. Most often, after we've made one healthy switch in our lives, we'll go on to make others. Making healthy substitutions one at a time makes change seem less formidable.
I made the switch to skim milk. It's now just become habit and I never think of buying anything else anymore. Now I've moved on. Bye-Bye white bread. It's nothing but whole grain now.
You can make other healthy substitutions in your day as well. Start taking the stairs instead of the elevator. Walk or ride with your kids to school.
So pick one thing today you can substitute with something healthier. Once that's become a habit, move on to something else.