I do try to follow it somewhat, but am not overly successfully.
I think Marcusrichard is spot on about the processing. As I understand it, because the refined starch enters the bloodstream as sugar too quickly, it triggers the production of insulin. The insulin prompts the body to convert the sugar to fat. This unfortunately means there is not enough easily accessible energy for the body to do its normal daily tasks so the signal comes from the brain that you are hungry so you eat more. If this is more refined starch, which it often is because the body becomes almost addicted to it, the cycle continues. This is why very often people feel hungry a short while after a MacDonalds etc. Because it takes more time for more complex carbs to be converted to sugar; the sugar, insulin, exercise cycle remains in balance. The body has the fuel it needs to work, the hunger signal is not triggered too soon and there is less sugar in the blood to be converted to fat.