Blood type has a lot to do with that...

Totally agree with fireguy... some people just do not do well with protein, period, and high dose of protein is just plain toxic to a body.

I believe the blood type has a lot to do with that, as the type O's are more of the protein and meat-eaters, whereas type A are definitely vegetarians.

I am type A and long time ago, without even knowing about this, tried the "then" version of Atkins diet (I don't even think it was called Atkins then). Anyway, made me so sick and exhausted and not able to function, I had to go off of it in less than a week).