The blood type diet is a popular diet that suggests your ABO blood group may determine the best foods for you to eat. However, very little scientific research supports its claimed benefits.
The blood type diet (BTD), also known as the blood group diet, was popularized in 1996 by Dr. Peter D’Adamo in his book “Eat Right 4 Your Type.”
In this book, Dr. D’Adamo claims the optimal diet and exercise regimen for any one individual depends on their ABO blood type. This may supposedly have benefits like improved health and decreased risk of chronic diseases.
He also claims that each blood type represents the genetic traits of our ancestors, such as which diet they evolved to thrive on.
Keep reading to learn more about the BTD and if it’s right for you.
What are the types of blood?
Your blood type is based on genetics, so the BTD categorizes foods to eat to reflect the diet your ancestors would have consumed.
Dr. D’Adamo claims that blood types evolved from different societies, so they each have an optimal diet:
- Type A, known as Agrarian, thrives on a mostly vegetarian diet.
- Type B, known as Nomadic, thrives on a high dairy diet.
- Type AB, known as Enigma, thrives on a mixture of type A and B diets.
- Type O, known as Hunter, is supposedly the oldest blood type and thrives on a high animal protein diet.
How does the blood type diet work?
One of the central theories of the BTD has to do with proteins called lectins. These are a family of proteins that can bind to carbohydrate molecules.
Plant-based lectins are sometimes referred to as antinutrients and may cause negative effects in humans, such as:
- nausea
- vomiting
- diarrhea
- abdominal pain
According to the BTD theory, eating the wrong types of lectins may specifically target different ABO blood types. They may cause red blood cells to agglutinate, or clump together, which could increase your risk of disease.
Some research suggests that a small percentage of lectins in raw, uncooked legumes can have agglutinating activity specific to a certain blood type. For example, a 2004 review suggests that raw lima beans may affect red blood cells in people with blood type A.
Overall, however, it appears that the majority of agglutinating lectins react with all ABO blood types. This means that lectins in the diet may not be blood-type specific, except for a few varieties of raw legumes.
Foods to eat
Below is a list of some foods to eat for each blood type, as recommended by Dr. D’Adamo.
Type AType BType ABType O• soy milk• eggs
• ghee
• broccoli
• carrots
• fennel
• kale
• pumpkin
• apricots
• blueberries
• cherries
• grapefruit
• pineapple
• brown rice flour
• oat flour
• tofu
• tempeh
• chicken
• turkey
• cod• beets
• broccoli
• carrots
• cow milk
• cottage cheese
• goat cheese
• mozzarella cheese
• yogurt
• kidney beans
• spelt bread
• oat bread
• almonds
• peppers
• cranberries
• grapes
• eggplant
• lamb
• venison
• cod
• halibut• watermelon
• cauliflower
• parsnip
• garlic
• figs
• eggs
• goat milk
• yogurt
• mozzarella cheese
• peanut butter
• lentils
• walnuts
• tofu
• curry
• red wine
• turkey
• cod
• lamb
• navy beans
• beets• beef
• lamb
• fish
• poultry
• kale
• onion
• spinach
• bananas
• sweet potatoes
• feta cheese
• almonds
• ginger tea
• eggs
• butter
• cheese
• artichokes
• mangos
• parsley
• olive oil
• flaxseeds
All four diets are mostly based on real, healthy foods, rather than processed foods.
So, even if you try one of these diets and your health improves, it doesn’t necessarily mean that it has to do with your blood type. The health benefits may simply be a result of eating healthier food than before.
Foods to avoid
Below is a list of some foods to avoid for each blood type, as recommended by Dr. D’Adamo.
Type AType BType ABType O• lima beans• garbanzo beans
• eggplants
• tomatoes• chicken
• corn
• soy
• lentils• chicken
• corn
• bananas
• fava beans• wheat
• soybean oil
• peanuts
• kidney beans
Does research support blood type diets?
Research on ABO blood types has advanced rapidly in the past few decades.
For example, the authors of a 2022 study cite many associations that have been made between blood types and various diseases, such as:
- hepatitis
- thrombosis
- cardiovascular diseases
- cognitive disorders
- circulatory system diseases
- infections
- tuberculosis
However, no studies suggest that these are related to diet. The minimal research that does exist on BTD doesn’t support Dr. D’Adamo’s claims that specific foods may cause benefits or harm to certain blood groups.
In a 2014 study of 1,455 participants, eating a type A diet of fruits and vegetables was associated with better health markers. However, this effect was seen in everyone following the type A diet, not just individuals with type A blood.
Similarly, a 2018 study of 973 adults with overweight found that matching a participant’s blood type with the respective recommended BTD didn’t impact the link between BTD and markers of cardiometabolic disease.
Lastly, in a 2020 study, 68 participants of different blood types ate a low fat vegan diet for 16 weeks. At the end of the 16 weeks, the researchers found no major differences in cardiometabolic changes between any of the groups.
Frequently asked questions
Does blood type diet work?
The short answer is: maybe. Some research suggests that eating certain foods is associated with better health markers. However, no research supports the claim that specific diets are better for specific blood types. The BTD removes the majority of unhealthy processed foods. This may be why it works, without any regard to the different blood types.
What blood type should eat meat?
According to Dr. D’Adamo’s BTD, all four blood types can eat meat. However, the recommended diet for type A is mostly vegetarian and only recommends poultry and fish, while the type O diet is mostly animal protein-based.
Is type O+ blood rare?
Type O+ blood is the most common type of blood.
Takeaway
The BTD was made popular by Dr. Peter D’Adamo in 1996. He proposed that there are optimal foods to eat for each blood type, which are based on their ancestors. That said, there is little research to support the benefits he claims.
Different diets work for different people. You may do well with a lot of plants and little meat (like the type A diet), while others may thrive eating plenty of high-protein animal foods (like the type O diet).
It’s important to speak with a healthcare professional if you’re unsure about which foods to eat. They can help you develop a nutrition plan that’s right for you.