Here is my 2 cents:
I agree that you really have to listen to your body. I have done a considerable amount of research into the vegan lifestyle (for ethical/health reasons), but have given that up since my body was rejecting it. Many of the veg foods have gluten as a base, so that eliminates a lot. Plus, I don't do very well on beans, seeds or nuts, so I would be extremely limited.
What I have figured out the past few years is that I do well on a higher protein diet...and that includes meat, but no diary. I have picked up the Paleo Diet (especailly after reading The Paleo Diet for Athlete