The Blood Type Diet encourages people to eat foods that will react positively with their blood type in order to prevent disease and keep us healthy and strong during aging. The diet was developed by Peter J. D’Adamo, a naturopath physician. He claims that our blood type is a genetic biomarker that will tell us which diseases we are susceptible to and how we can keep ourselves healthy as we age. The premise behind his theory is the body’s ability to recognize itself from non-self. His theory states that lectins (proteins; think “molecules”) in food will react differently with the ABO blood types. The idea is to eat foods that are compatible with certain blood types. Eating foods not compatible will lead to certain illness and disease.
What's the rationale behind the diet?
He suggests very specific foods to eat for each blood type A, B, O, or AB. He goes further to claim there are certain exercises that are more beneficial for the specific blood types. He has based the particular foods on the history and time in evolution of the blood types and the types of foods that were eaten by our ancestors. For example, D’Adamo believes the type O bloodline to be the oldest and calls it the hunter. Since our ancestors of that time ate lean meats, fish, and not too many grains and breads, then you should too. He calls the A bloodline the cultivator and believes it evolved during the agricultural movement; therefore, you should eat more vegetarian-like. He calls the B bloodline the nomad because this evolved during a time when people started eating dairy. Of course, if this is your bloodline, then dairy should be your diet of choice. The AB blood group is the enigma and is the most recent to evolve. This group can eat a mix between foods from blood type A and B.
The scientific community agrees that there is no scientific evidence to substantiate his claims. Further, his premise that lectins in food will react with the ABO blood types is not supported by scientific research.
Will I lose weight?
There is anecdotal evidence of people losing weight and claiming to have improved digestion and increased energy levels. The weight loss has most likely occurred for the same reason that many other diets work. When macronutrients and certain foods are eliminated, your body goes through a change and often there is a change in the caloric intake as well.
Sticking to a variety diet will ensure that you are getting adequate nutrition. Try cutting the portion sizes of well-rounded meals, and choose to eat lean meats, lots of veggies and fruits, healthy grains, and some dairy (unless you’re lactose-intolerant). There is plenty of evidence to support the notion that cholesterol-laden foods can be harmful for your health. Choose a diet that has been shown to be heart healthy. Your life will thank you!