One thing to consider is this......
All of these diets that have been concocted over the years are all geared toward non training sedentary individuals. Many of these diets fall well short of our protein requirements and will start to eat away at muscle before too long. Best way to diet is work to ratios of macro nutrients. Get the ratios right and you will be absolutely amazed at the results and how you feel.
Do you think the caveman actually knew what his blood type was? Did the earlt sttlers know what the hollywood diet was? I know that is a bit extreme but think about it. I personally do not believe in these diets because our bodies are very adept at change, to our environment and our dietary habits. Sure some foods will not agree with you but I think we can all figure that out for ourselves, we do not need some guru to tell us that it is bad for us!