What foods should AB blood type avoid?

November 1, 2025 •

5 min read

The blood type diet, a concept introduced by Dr. Peter D'Adamo in his 1996 book, suggests that an individual's blood type can influence their optimal dietary choices. This is particularly relevant for those with AB blood type, the rarest and most recently evolved blood type, which inherits traits from both A and B blood types. For AB individuals, avoiding certain foods is recommended to counter potential digestive issues stemming from naturally lower stomach acid.

Quick Summary

The AB blood type diet suggests a tailored approach to eating, recommending a focus on specific food groups while advising against others due to genetic predispositions. Key foods to avoid include processed meats and certain grains like corn, which are believed to be poorly digested by AB types due to lower stomach acid. Limiting these foods is thought to enhance digestion and metabolic health.

Key Points

Processed and Cured Meats: Avoid bacon, ham, and other processed meats completely due to potential digestive and health risks.
Corn and Buckwheat: Steer clear of corn, corn products, and buckwheat, as their lectins are considered incompatible with the AB blood type.
Select Grains and Legumes: Limit or avoid kidney beans, lima beans, and soba noodles due to potentially problematic lectins.
Restrict Certain Fruits: Bananas, oranges, and coconuts are on the avoid list, with plums, cherries, and berries being more beneficial alternatives.
Limit Dairy and Fats: Avoid whole milk, butter, blue cheese, and American cheese, and stick to beneficial fats like olive oil.
Focus on Digestibility: Due to naturally lower stomach acid, AB types should opt for smaller, more frequent, and easily digestible meals.
Consult a Professional: Always seek advice from a healthcare professional or dietitian before starting a new diet plan.

Understanding the AB Blood Type's Unique Dietary Needs

Individuals with blood type AB possess the characteristics of both A and B blood types, leading to a unique dietary profile. For example, they have the Type A trait of low stomach acid production, yet also inherit the Type B trait of adapting to meat consumption. This combination can make digesting certain foods difficult, which proponents of the blood type diet believe can negatively impact health. The theory suggests that lectins—proteins found in food—can react differently with each blood type and cause agglutination, or clumping, of blood cells when incompatible foods are consumed. For AB types, certain foods contain lectins that are believed to interfere with proper digestion and metabolism. This has led to specific recommendations on what foods should be avoided or consumed sparingly.

Meats and Poultry to Steer Clear Of

Because of their lower stomach acid, people with blood type AB should limit their intake of certain meats that are hard to digest.

Processed and Smoked Meats: Bacon, ham, and other cured or processed meats should be avoided completely. The preservatives and processing chemicals are believed to be especially harmful to AB types and can increase the risk of certain diseases.
Beef and Chicken: Though often staples in many diets, beef and chicken are recommended to be consumed less often by AB types. These meats are dense and can put a strain on a digestive system with lower stomach acid, potentially leading to fat storage and weight gain.
Other Red Meats: A variety of other red meats, such as pork and veal, are also on the 'avoid' list for AB types for similar digestive reasons. Lamb, mutton, and turkey are often suggested as better alternatives.

Grains and Legumes: Navigating Your Carbs

Navigating grains and legumes can be a mixed bag for AB blood types. While many are beneficial, some should be avoided.

Corn: Both corn and corn-based products are considered harmful for AB types. The lectins in corn are thought to interfere with insulin regulation, potentially contributing to weight gain and blood sugar imbalances.
Buckwheat: This pseudocereal is on the avoid list for AB types.
Kidney Beans and Lima Beans: These legumes contain lectins that are considered incompatible and should be avoided to prevent potential digestive issues.

Fruits and Vegetables to Limit

For a blood type that thrives on fruits and vegetables, there are still a few that should be avoided.

Oranges and Bananas: These are noted to be difficult for AB types to digest. It is suggested to opt for more compatible, alkaline fruits like plums, cherries, and berries instead.
Coconuts: This includes coconut and all its products.
Avocados: While a healthy fat for many, the blood type diet suggests avocados should be avoided by AB types.

A Deeper Look at Dairy and Fats

Dairy and fats are another category with specific recommendations for AB types. While some dairy is well-tolerated, certain types are not.

Whole Milk and Buttermilk: The high-fat content of these items can be problematic for a system with lower stomach acid.
Blue Cheese and American Cheese: Specific lectins in these cheeses are believed to cause issues for AB blood types.
Certain Oils: Corn oil and sesame oil are on the avoid list, while olive oil is highly beneficial.

The Role of Lectins and Overall Health

According to Dr. D'Adamo's theory, the primary reason for avoiding these foods is the presence of certain lectins that can have adverse effects on health. In the case of AB types, these reactions could potentially lead to inflammation and exacerbate a naturally weaker immune system. The diet emphasizes that consuming the right foods can counteract these negative effects, leading to improved digestion, metabolism, and immunity. While the scientific community remains divided on the validity of the blood type diet, many who follow it report positive outcomes.

A Comparative Look at Diets for Different Blood Types


Food Category	Type A Recommendations	Type B Recommendations	Type AB Recommendations	Foods to Avoid for AB Type
Meats	Vegetarian diet encouraged, limit red meat.	Balanced diet with meat, avoid chicken.	Moderate, lean protein like lamb, fish.	Chicken, beef, pork, processed meats.
Dairy	Avoid or limit dairy products.	Moderate dairy, including milk and cheese.	Moderate dairy, especially yogurt and kefir.	Whole milk, butter, blue cheese, American cheese.
Grains	Whole grains and cereals encouraged.	Wheat and corn to be avoided.	Oats and rice are beneficial.	Corn, buckwheat, cornmeal, soba noodles.
Fruits	All fruits generally good, avoid certain tropical fruits.	All fruits generally good, avoid certain tropical fruits.	Plums, berries, and alkaline fruits encouraged.	Bananas, oranges, coconuts, mangoes.
Fats	Olive oil is beneficial.	Olive oil is beneficial.	Olive oil is beneficial.	Corn oil, sesame oil.

Making Conscious Dietary Choices

For those with blood type AB, adopting a diet that emphasizes fresh fruits, vegetables, and beneficial proteins like fish and lamb, while limiting specific incompatible foods, is key according to this diet. The lower stomach acid of AB individuals means that easily digestible, balanced meals are preferable to heavy, processed foods. By focusing on foods that support their digestive system and avoiding those that can cause inflammation or metabolic issues, AB types can work towards improved overall wellness. As with any diet, individual reactions and sensitivities can vary, so listening to your body is always recommended. Always consult a healthcare professional before making any significant dietary changes.

Conclusion: Strategic Eating for AB Types

In conclusion, understanding what foods should AB blood type avoid is crucial for those following this dietary plan. The emphasis is on limiting or eliminating poorly digested meats like chicken and beef, as well as specific grains and legumes such as corn, buckwheat, and kidney beans. By favoring foods that are better suited for their unique digestive and metabolic profile, AB individuals can potentially mitigate health risks associated with a weaker immune system and low stomach acid. Making these strategic dietary choices is not just about avoiding certain items, but about building a balanced, health-supportive diet that caters to the specific genetic makeup of the AB blood type.

Frequently Asked Questions

According to the blood type diet, individuals with AB blood have lower stomach acid, which makes digesting chicken more difficult. The theory suggests this can lead to metabolic issues and hinder weight management.

No, corn and corn-based products are generally not recommended for AB blood types. The lectins in corn are believed to interfere with insulin regulation and cause issues for AB individuals.

Beef is considered a food that should be limited for AB blood types, not strictly avoided like processed meats. The difficulty in digesting red meat due to low stomach acid is the primary reason for this recommendation.

Fruits to avoid include bananas, oranges, mangoes, coconuts, and guavas, among others. These are believed to be less compatible with the AB digestive system.

Yes, sunflower seeds, sesame seeds, and poppyseeds are recommended to be avoided by AB blood types. Peanuts and walnuts are considered beneficial.

Dr. D'Adamo's theory suggests that due to low stomach acid, AB types do not metabolize meat efficiently. This can lead to the meat being stored as fat rather than being used for energy.

The scientific evidence supporting the blood type diet is limited, and the concept remains controversial within the medical community. While some people report positive results, experts often recommend focusing on a balanced diet rich in whole foods, regardless of blood type.

No, some dairy is acceptable and even beneficial, such as kefir, yogurt, and goat cheese. However, specific types like whole milk, butter, blue cheese, and American cheese should be avoided.