The blood type diet was developed by Peter D'Adamo, who wrote "Eat Right for Your Type". The diet is based on the fact that there are 4 different blood types, and each blood type group should eat differently, exercise differently and choose different medical options.
The four blood groups are types O, A, B and AB. Each of the blood types is given a profile of what types of food each should eat.
What Foods Are Allowed?
Type O is considered to be the high protein group, or the meat eaters. Fruits, vegetables, meat and fish are allowed. For weight loss, foods to be avoided include grains, beans and legumes.
Type A is called the vegetarian group. Recommended foods for this group are fuits, vegetables, grains, tofu, seafood, beans and legumes. The foods to be avoided for weight loss are meat, dairy and wheat.
Type B is the balanced omnivore group. Fruits, vegetables, meat, dairy, grains, beans and legumes are recommended. This group is the most varied and flexible. Foods not helpful for weight loss are wheat, peanuts, corn and lentils.
The final group, AB, is considered to be a mix of group A and group B. Fruits, vegetables, grains, legumes, beans, seafood, dairy and tofu are acceptable. To enhance weight loss, avoid kidney beans, corn, red meat and seeds.
The theory behind the blood type diet is that there are proteins in food called lectins, and they are digested differently by each blood type.
According to D'Adamo, there are specific foods that are recommended for each blood type, ones to be avoided and those that are neutral.
How Much Can You Lose?
There is no specification as to how much you can lose. The blood type diet is given more as a lifestyle diet, as opposed to a fad diet, so it's meant to be used permanently.
Does It Work?
Many people claim to have had success with the blood type diet, but the science behind it just isn't there. The scientific community does not endorse the diet simply because there is no real evidence that it works.
Is It Safe?
The biggest danger of the blood type diet is the risk of having an unbalanced diet. Additionally, people who have health related issues, such as diabetes, coronary artery disease, liver disease, or children, teens and pregnant and breastfeeding women should seek medical advice first.