The Eat Right for Your Type diet (Blood Type Diet) advises people to eat certain foods based on their blood type: A, B, AB, or O and the genetic heritage that is contained in the blood type.   Among other principles plan posits that each blood type digests food proteins (called lectins) differently and that eating the wrong food proteins can cause ill effects on the body—including slower metabolism, bloating, and even certain diseases. According to this diet, avoiding bad food proteins will help a person achieve better health. 

• Blood Type A people flourish on a vegetarian diet
• Blood Type B people should avoid corn, wheat, buckwheat, lentils, tomatoes, peanuts, and sesame seeds in order to maintain a healthy weight.  Other foods that Type Bs should consume to encourage weight loss are green vegetables, eggs, beneficial meats, and low-fat dairy.  Type Bs should avoid chicken, and replace it with beneficial meats such as goat, lamb, mutton, rabbit, and venison.  
• Blood Type AB people should avoid caffeine and alcohol, especially in stressful situations.  Type ABs should focus on foods such as tofu, seafood, dairy, and green vegetables to lose weight and avoid all smoked or cured meats.  A wide variety of seafood and some dairy is also beneficial for Type AB – especially cultured dairy such as yogurt and kefir.   Type AB people should also pay attention to food combining principles.
• Blood Type O people can efficiently digest and metabolize meat because they tend to have high stomach-acid content. They should use lean, chemical-free meats, poultry, and fish.   Type Os should avoid gluten found in wheat germ and whole wheat products and certain beans and legumes (lentils and kidney beans) all of which contribute to weight gain.   Type Os have a tendency to have low levels of thyroid hormone or unstable thyroid functions, which also cause metabolic problems; therefore, it is good to avoid food that inhibits thyroid hormone (cabbage, brussels sprouts, cauliflower, mustard green) but increases hormone production (kelp, seafood, iodized salt).  Type Os should eat fruits of alkaline nature such as berries and plums and severely restrict the use of dairy products.   Type Os of African ancestry should eliminate dairy foods and eggs altogether.