Blood Type Diet Basics

The Blood Type Diet is based on the theory that the antigens that determine your blood type also affect the way your body digests foods. In his book, "Eat Right 4 Your Health," naturopathic physician Peter D'Adamo argues that by eating foods compatible with your blood type, you can not only lose weight, you can also help to relieve chronic medical conditions and to ward off certain diseases. The diet plan has drawn criticism from other medical professionals who cite a lack of evidence to support the theory.

History

D'Adamo bases his blood type theory on his research into medical history, anthropology and genetics and the way the four main blood types evolved in humans. For example, he says O is the oldest blood type and was present during the hunter-gatherer era. So, today's type O individuals will do best on a diet like the ancient high-protein diet of their ancestors. Type A came along as early man was more settled, so D'Adamo argues today's Type A's do better on a more vegetarian-style diet.

Foods to Eat

D'Adamo recommends a diet rich in meats and fish for Type O's. Certain vegetables, nuts, seeds and eggs are also allowed on the diet. For Type A's, D'Adamo recommends a diet of vegetables, fruit, grains, beans, legumes, nuts and seeds. Type B's can eat a diet drawing from the food lists of types O and A. People with type-AB blood, the newest group, can eat a combination of foods from the A and B lists. However, D'Adamo says they do best with a mostly vegan diet.

Foods to Avoid

The list of foods to avoid is equally important on the Blood Type Diet. D'Adamo says there are certain foods responsible for much of the weight gain for each blood group and certain foods that can cause a range of medical problems. He says Type O's should avoid dairy, grains, legumes and beans. A person with type-A blood should stay away from meats and dairy and limit intake of wheat products. Type B's should avoid chicken and shellfish and are said to gain weight from corn, buckwheat, lentils, peanuts and sesame seeds. D'Adamo finds Type AB's should follow the avoid lists for both types A and B, with the exception of tomatoes.

Exercise Plan

People on the Blood Type Diet are not only encouraged to eat based on their blood type, they are also encouraged to pursue physical activities best suited to their type. D'Adamo says Type O's, the descendents of those early hunter-gatherers, feel best when they engage in intense exercises such as aerobics and contact sports. He recommends Type A's pursue calming exercises, such as yoga and tai chi. For Type B's, he recommends moderate activities such as brisk walks, swimming and bicycling are best. Type AB's do best with a combination of exercise for blood types A and B.

Warning

Whenever you eliminate entire food groups from your diet, you run the risk of losing important vitamins and minerals, too. D'Adamo sells a line of supplements designed to complement his diet program, but nutritionists say most people should be able to get all the vitamins and minerals they need by eating a healthy, well-balanced diet. Before beginning any diet, it's best to check with your doctor to discuss what's right for you.