Wow that is so interesting that you mention blood Sugar problems because that was my intention when asking this question. When I followed the Blood Type Diet I felt that I was on a roller coaster of ups and downs and those are awful especially when you're an athlete. I find it bogus to say that these 4 diets could possibly be most beneficial for everyone. Can you really sum up the entire population into just 4 categories? I believe that it can help some people especially those who were lactose intollerant heavy diary consumers and then stop using diary all together. I do not tollerate diary well myself, but then again most of our population does not. I am going to have to check out this metabolic diet. I am on a mission to learn what foods suit my body best and formulate my own personal principles. Every body is so unique. I feel much more consistent energy when I eat more protein and fats and do not spike with the carbs... How do you do with fruits? Sugary dried fruits are yummy, but I found that sometimes just too much Sugar for my body. Thank you for your advice and personal experience!