I get questions all the time about diets based on a person’s blood type. Frankly, I don’t believe in them. Below is a piece written by Mark Sisson. His explanation is consistent with my thinking about diets based on blood types.
Blood Doc John
Metabolic and Blood Typing Diets
Humans share 99.9% of the same human genome. The other .1% of genetic variation would be your height, body type (ecto, endo, mesomorph), eyes, skin color, etc. The important thing is that our metabolic machinery works the same way for just about everyone. We burn and store fat the same way, we build muscle and fight microbes the same way – it’s only the degree to which we do those successfully that can be ever-so-slightly impacted by our unique family genes.
Nevertheless, For example, the premise of Eat Right For Your Type is that the four main blood groups (Type O, A, B and AB) react differently to food and carry disparate recommendations (Type A blood should be vegetarian, Type O should be carnivore, Type B should emphasize dairy, etc.).
The premise metabolic typing diets is that we have distinctive metabolisms (based on our ancestral heritage; indeed blood type is believed to be a good indicator of certain genetic heritage attributes) that are best served by a corresponding nutrition profile of “protein type” (high protein and fat, low carb), “carb type” (dominant carbs, moderate protein, low fat) or “mixed type”.
Unfortunately for the proponents of these diets, there is respected evidence that we diverged in blood types millions of years ago, invalidating the premise entirely that Type O blood represents a descent from hunter-gatherers, Type A from agriculture humans and Type B from herding nomads. Because the last 200 years have seen so much mixing of races and ancestries, blood type heritability is now no different from hair color. You may as well eat according to your hair or eye color – seriously!
There are, indeed, other individual factors that influence our nutritional needs and sensitivities, but I’d argue that these don’t have anything to do with where great-, great-, great-, great- (and so on) grandpa came from. Ultimately, personal preference far outweighs any concerns about your blood type, when it comes to compliance and overall dietary satisfaction. If you descended from Eskimos, but dig tropical fruit, hate fish and love turkey, knock yourself out – you’ll be just fine.
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