WHAT the food provides is the issue. Natural or fake, you decide. Move your body everyday. It doesn't matter what you do, just do something. Your body will depend on the consistency, and that's good.
Exercise is a good way to replace bad habits, too.
If you want to quit smoking, let's say, replace the habit with exercise. Find what type of exercise you will adopt permanently into your life, and never quit. Biking around the neighborhood after work, walking around the block before the day begins, swimming ten laps every day, rowing while you watch the evening news, whatever - your body will depend on it. Avoid fake foods. Vitamin and mineral rich foods are what I refer to as natural foods.