Dr. Peter D'Adamo is a naturopathic physician who has developed a system to help people choose a diet based on their blood type. His book, Eat Right For Your Type, provides a list of foods that people should eat and those they should avoid depending on their blood type.
People with type O blood are the most common. Type O people usually have a high amount of stomach acid and have a tendency toward stomach ulcers. Type O's are thought to thrive on high protein diets consisting of lean red meats, poultry, eggs, and fish. Type O people should avoid excess carbohydrates, especially wheat, corn, and potatoes. These people also are advised to avoid dairy products, including milk and most cheeses. The best type of exercise for these people is strenuous aerobic exercise performed at least 3 times a week. Common diseases in this group include blood clotting disorders, low thyroid, arthritis, and allergies.
The next most common blood type is type A. These people usually have low stomach acid so they are thought not to digest animal proteins like type O. Type A people usually do better on a vegetarian diet. Their bodies prefer high carbohydrate and low fat diets. Type A's are told to avoid wheat and most dairy products. The best type of exercise for these people is something calming, such as yoga, tai chi, or walking. Common diseases in this group include heart disease, cancer, anemia, liver and gall bladder problems, and type I diabetes.
People with type B blood are thought to have a strong immune system and are tolerant of many foods the other groups cannot eat. Type B people are best described as an omnivore and do well on a balance of meat (except chicken) and vegetables. Type B's are considered the only group that can effectively digest dairy products but they should avoid wheat products. The best type of exercise for type B's is moderate aerobic exercise that requires mental and physical balance (eg, tennis, cycling, hiking). Common diseases in this group include diabetes, chronic fatigue, multiple sclerosis and lupus.
Type AB is the least common blood type. Their food choices are a combination of the type A and type B profiles. Type AB's are thought to have a sensitive digestive tract and a strong immune system. Type AB's have a low stomach acid so they should eat meat in moderation. They can eat some types of wheat in moderation and can eat some types of dairy. Type AB people also benefit from relaxing type exercise, like tai chi or yoga combined with moderate physical activities, such as hiking and cycling. Common diseases in this group include heart disease, cancer, and anemia.
1. D'Adamo PJ & Whitney CA: Eat Right For Your Type. G.P Putnam, NY, NY, 1996.