The Diet, Eat Right For(4) Your Type is based on the works of Dr. Peter D'Adamo, who found (in his extensive research) that people do better, in all aspects of life, when they tailor their diet to their specific blood types.
Here's a quick break down.
Type A's have thicker blood than other blood types, a sensitive immune system, and should not consume dairy products, animal fats and meats. They should basically stick to high carb, low fat fruits and veggies.
Type B's should eat a balanced diet such as fruits and vegetables, grains, fish, dairy, meat..duh! But avoid chicken.
Type AB's should consume a mostly vegetarian diet, and only on rare occasions some fish, meat (no chicken) and dairy.
Type O's are the oldest blood type. They should stick to a high protein diet, low in carbs with fruits and vegetables. They should limit the intake of wheat products, corn as well as avoid dairy products and most nuts.
The diet is claimed to be a solution to staying healthy, living longer & achieving your ideal weight. And I must say, it's pretty convincing.
Fit's Tip: If you're not sure what type you are, your driver's license may reveal it. If you're interested in doing this diet, you should definitely buy the book ($16.47). There is A LOT more to it than my summary above and a lot of interesting stuff about blood types and disease as well as recipes specific to each type. Buy it here.