The Blood Type Diet: Fad or Functional? How To Know If This Trendy Diet Is Right For You

In 1996, a naturopathic physician named Peter D’Adamo published the book Eat Right 4 Your Type, which gave diet and lifestyle advice based on blood type. Immediately, it was a massive success, selling over 7 million copies, making the New York Times bestseller list, and translated into 52 different languages. (1) 

Now, decades later, it’s still incredibly popular, despite the hundreds of nutrition and lifestyle books that have come after it. But what is the science behind the blood type diet? Does it really make sense? Read on for my thoughts.

What is the blood type diet? 

The basic theory behind the blood type diet is that our blood type creates differences in our physiology that are substantial enough to warrant adjustments in lifestyle. For example, on his website D’Adamo describes Type O as the “oldest of the blood types” writing that those with type O blood display traits like “exceptional strength, a lean physique, and a productive mind” but also an “overactive fight or flight response reminiscent of early survival instincts.” He then goes on to say that type A blood types entered the genetic landscape at the time of animal domestication and agriculture. “Thriving on a mostly vegetarian diet rich in soy protein, fruits and vegetables, Blood Type A individuals are sensitive, creative, analytical thinkers,” he writes. 

Eating For Your Blood Type

According to a Harvard Health Blog (2) on the topic, the blood type diet gives the following recommendations to eat right for your blood type: 

• The O blood type diet should include high-protein foods and eat lots of meat, vegetables, fish, and fruit but limit grains, beans, and legumes. To lose weight, seafood, kelp, red meat, broccoli, spinach, and olive oil are best; wheat, corn, and dairy are to be avoided.
• The A blood type diet should include fruit, vegetables, tofu, seafood, turkey, and whole grains but avoid meat. For weight loss, seafood, vegetables, pineapple, olive oil, and soy are best; dairy, wheat, corn, and kidney beans should be avoided.
• The B blood type diet should include a diverse diet including meat, fruit, dairy, seafood, and grains. To lose weight, type B individuals should choose green vegetables, eggs, liver, and licorice tea but avoid chicken, corn, peanuts, and wheat.
• The AB blood type diet should include dairy, tofu, lamb, fish, grains, fruit, and vegetables. For weight loss, tofu, seafood, green vegetables, and kelp are best but chicken, corn, buckwheat, and kidney beans should be avoided.

If this all seems a little far-fetched to you, you wouldn’t be the first to think so. In fact, one Germann scientist is quoted as saying “It is difficult not to perceive the whole thing as a crass fraud.” (3)

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.

Our content may include products that have been independently chosen and recommended by Dr. Will Cole and our editors. If you purchase something mentioned in this article, we may earn a small commission.