When I first started I wouldn't feel well... upset stomach, achy joints, etc. Now, nothing.
For example - the other night, after too much beer and wine tasting I enjoyed a baguette with butter for dinner, chocolate malt balls and pink Starbursts (darned candy bulk bins!) and some roasted marshmallows. The next morning I woke up feeling fine. I went for a run (the same 5k loop I had done the day before in a normal paleo state) a full minute and a half faster. Its mornings like that when I wonder if maybe I should live on bread, wine and chocolate - with a few pink Starbursts thrown in.