© Shutterstock

The diet -

Naturopathic physician Peter D'Adamo published a book in 1996, 'Eat Right 4 Your Type,' where he outlined the potential benefits associated with eating foods that correspond to blood type.

© Shutterstock

The theory -

Blood type diet theory suggests that those with group A blood should eat a mostly vegetarian diet, and those with group O should focus on high animal protein.

© Shutterstock

The theory -

Those with group B should eat dairy products, and people with AB blood should eat a diet that has elements of both the A and B diet.

© Shutterstock

Why? -

ABO blood groups are determined by antigens present on the surface of blood cells. A antigen, B antigen, both, or neither may be present, giving the blood types A, B, AB, or O.

© Shutterstock

Why? -

The blood type diet proposes the idea that blood type can affect how certain foods are digested, due to evolutionary history.

© Shutterstock

Why? -

D'Adamo put forward the idea that, by extension, eating according to your blood type can have health benefits.

© Shutterstock

Type O -

Type O belonged to some of our most ancient ancestors. The recommended diet for this type is based on the diet of the earliest hunter-gatherers.

© Shutterstock

Type O -

The diet claims people with type O blood are best suited to eating animal protein. They are considered to have the most ease in digesting meat and fat.

© Shutterstock

Type A -

The blood type diet recommends those with type A blood follow a natural, organic, vegetarian, or mostly vegetarian food plan.

© Shutterstock

Type A -

The diet claims people with type A blood have been shown to have lower levels of stomach acid than other blood types, making it difficult for them to digest meat.

© Shutterstock

Type B -

The blood type diet claims that type B people are generally able to digest high fat foods, and should prioritize milk and dairy products to have more energy.

© Shutterstock

Type B -

Supposedly, group B blood was developed among nomadic tribes who had a high consumption of dairy. Prehistoric people with type B blood had to be flexible and creative to survive in new conditions.

© Shutterstock

Type AB -

When people with type A and type B blood reproduced together, it resulted in the AB blood group. Therefore, this group can take diet elements of both types.

© Shutterstock

Blood type health -

In the 1950s and '60s, researchers looked into the risk of coronary artery disease between the blood types, finding type O to be at a lower risk.

© Shutterstock

Blood type health -

Other studies have suggested an increased risk of higher total cholesterol and LDL (bad cholesterol) concentrations among people with blood type A.

© Shutterstock

Questions -

The findings led to questions being raised about the kinds of food that could be more beneficial from one blood type to another. However, research is lacking to back up the theories behind the blood type diet.

© Shutterstock

Blood type O foods -

According to the blood type diet theory, those with type O blood should eat meat, fish, vegetables (broccoli and spinach in particular), and fruit.

© Shutterstock

Blood type O foods to avoid -

They should limit grains, beans, and legumes, and avoid wheat, corn, and dairy if they're attempting to lose weight.

© Shutterstock

Blood type A foods -

Those with type A blood should eat fruit, vegetables, tofu, seafood, turkey, and whole grains, according to the blood type diet.

© Shutterstock

Blood type A foods to avoid -

It's recommended type A's avoid red meat altogether. They should also avoid dairy, wheat, corn, and kidney beans if they're trying to lose weight.

© Shutterstock

Blood type B foods -

The blood type diet theorizes those with type B should eat a diverse diet, which includes meat, dairy, seafood, grains, and green vegetables.

© Shutterstock

Blood type B foods to avoid -

If type B's are trying to lose weight, they're advised to cut chicken, corn, peanuts, and wheat from their daily food intake.

© Shutterstock

Blood type AB foods -

Type AB should eat tofu, dairy, lamb, fish, grains, and vegetables, according to the diet. If they're trying to lose weight, they should avoid foods like kidney beans, chicken, corn, and buckwheat.

© Shutterstock

Studies -

In studies, it was discovered that those with type A blood who followed a type A diet did experience health improvements... as did those who followed it with type B, O, and AB blood types, too! 

© Shutterstock

Studies -

It's probably common sense: a diet rich in vegetables, fruits, and whole grains that limits red meat is associated with cardiovascular benefits.

© Shutterstock

Cardiovascular health and cholesterol -

Similarly, the AB diet type advises limiting butter while eating eggs and fish. These foods have been linked to more favorable test results for heart health and blood sugar management in all blood types.

© Shutterstock

Type A eating habits -

According to the available research, eating patterns similar to the A blood group diet tend towards people having a lower body mass index (BMI), waist circumference, and insulin levels.

© Shutterstock

Type O eating habits -

Regardless of blood type, the type O diet recommendations have been associated with lower triglyceride levels when tested.

© Shutterstock

The bottom line -

There's no quality evidence available to demonstrate that blood type impacts dietary choices. What research is available shows that the health benefits from eating according to each suggestion are applicable to every blood group type.

Sources: (Verywell Health) (Healthline) (Cleveland Clinic)

See also: This is how your blood type can affect your health

© Shutterstock