well, I think it's that your system is clean and you're noticing the affects foods have on your system now. when we're shoving all of those things in our systems on a regular basis we just feel like crap in general.
I know that I'm sensitive to Sugar and feel crazy from it. other people drink soda everyday. I guess their bodies grow immune or something. the less I have, the more noticable the negative effects when I do have it.