Yeah it is very rare but we are suppose to be the more evolved species--lol. But I thought the book was a bunch of crap so I tested it. I ate what it told me to eat (benefical foods) for 1 month and then I ate foods (negative foods) for 1 month. I felt like crap that 2nd month and I felt great the 1st month. So I went back to the book diet. And now I feel great. My wife is a B and the book told her to eat meat and stuff like that. Well she was never a big meat eater. She tried the book and she has lost weight and feel wonderful as well. Very bizarre how it all works for us.