We're not convinced by the science behind the Blood Type Diet, but it does have some popularity, so we wanted to review it. The diet is based on the premise that an individual's diet should be calibrated toward his or her blood type--so there are actually four diets within naturopath Dr. Peter J. D'Adamo's Eat Right For Your Type book--one for types O, A, B, and AB. Dr D’Adamo believes blood group determines how our bodies deal with different nutrients. Dr D’Adamo believes that because blood types evolved at different times throughout history, we should eat a diet based on the types of foods our ancestors typically ate at the time when our blood type developed--type O at 50,000 BC, type A at 15,000 BC, type B at 10,000 BC, and finally AB at just 1,000 years ago.
The theory is interesting, but the vast majority of scientists and doctors simply don't buy it--there's just not the rigorous scientific substantiation that this is true. So much is based on anecdotal reports ("I felt fatigued before and now I'm on my type diet, I'm bursting with energy.") There is a bibliography, but the diet appears to based on the author's own research without any unbiased clinical trials. In our opinion, this diet has many of the hallmarks of a fad diet without scientific backing, so we'd steer clear.
There are many little niggles as well--for instance, the writer says one type should eat turnips, but not chinese cabbage, when they are simply different strains of the same plant species. Type O is supposed to avoid cabbage and brussels sprouts, but to eat kale, broccoli and collard greens--again, same types of plants.
Of course, this hasn't stopped the diet from gaining significant popularity; the 1997 book was a bestseller and celebrities like Liz Hurley and Courtney Cox-Arquette swear by it. Nonetheless, we don't think this sort of pseudo science is worth following.
Menu: Again, the diet varies by the four basic blood types. For Type O, the oldest and most common, is a variation on the low carb Atkins diet with plenty of meat fish, etc, and lots of exercise like our hunter-gatherer ancestors of this period did. Type A diet is the second most common, and reflects a more farm lifestyle with more grains and veggies but little meat, while you should have calming exercise like yoga or golf. Type B is only 10% of the US population, and has the least dietary restrictions, able to thrive on all sorts of foods, and exercise should have a mental component, so plenty of hiking, tennis, or swimming. Finally the rare AB type should eat a combination of foods for types A and B.
Of course following this diet can be tough in a family with different blood types--if one is an Atkins style O and another a veggie heavy Type A for instance.
Prices: Dr. D'Adamo's book on Amazon costs around $15. Prices vary for the diets--of course the Atkins-style Type O diet heavy on meats can be more expensive for instance.