What Is It?
The “eat right for your type” diet, also
known as the blood type diet, advises people to eat certain foods based on
their blood type: A, B, AB, or O. This diet was developed by naturopathic
doctor Peter D'Adamo in his book “Eat
Right for Your Type: The Individualized Diet Solution to Staying Healthy,
Living Longer & Achieving Your Ideal Weight.” D’Adamo claims that
each blood type digests food proteins (called lectins) differently. He believes
that eating the wrong foods containing the wrong lectins can cause negative
effects on the body. These effects include slower metabolism, bloating, and
even certain diseases, such as cancer.
D'Adamo’s theory relies on evolutionary theory
associated with each blood type, with a corresponding diet and fitness plan.
D'Adamo says quick fight-or-flight responses are
caused by having type O blood because this ancestral blood type is finely tuned
to respond to the stresses of ancient times. According to the diet plan, people
with this blood type will benefit from a high-protein diet of lean meats and
fish, limited grains and breads, and intense exercise.
After agriculture reduced the need for
hunter/gatherer lifestyles, this blood type developed in order to better use
nutrients from carbohydrate-based foods, according to D’Adamo.
The type A diet plan emphasizes soy proteins,
grains, and vegetables, and restricts red meat. It also suggests a lighter
D'Adamo traces the history of this blood type
back to nomadic Asian peoples. He describes people with this type as being more
genetically suited to thrive in varied conditions. As a result, he says type B
dieters can tolerate dairy products and can also enjoy meat and most produce.
This plan restricts corn, wheat, lentils, tomatoes, and peanuts. It suggests moderate
This blood type shares characteristics with types A and B. Type AB
dieters are encouraged to avoid meats but can safely eat tofu, seafood, dairy,
and most produce. This plan suggests a mix of calming and rigorous exercises
for a balanced fitness routine.
The blood type diet promises that it
understands you as a "biochemical individual." It claims that
changing your diet to be based on foods that are determined to be beneficial
for your blood type will lead to weight loss, increased energy, and lasting
health. The promise of this diet is less about weight loss and more about
improved health, mental clarity, and resistance to disease. The plan offers
individualized eating plans for better health.
Pros and Cons
This diet plan emphasizes that every person
is different when it comes to dieting, which is a sound foundation. There is no
caloric restriction on this diet. This means less chance of the hunger pangs
normally associated with dieting, but it may not produce much actual weight
loss. It does encourage a more active lifestyle of varying degrees of exercise
(based on blood type). There also seem to be plenty of people who have reported
having success on this diet plan. D'Adamo's website has lots of information and
support forums for those who are interested in exploring his approach.
The blood type diet runs into problems with
the lack of research available to back up D'Adamo's claims. The medical
community doesn’t support the idea that blood type has many connections at all
to health, let alone the benefit of specific diets for each blood type. One study found that D’Adamo’s diet plans
did have some health benefits, but that these didn’t correspond to blood type. For
example, anyone following the type A diet was more likely to have a lower BMI,
smaller waist, and lower blood pressure, whether or not their blood was type A.
In response, D’Adamo said that the researchers didn’t
evaluate enough different foods to properly test the effects of the blood type
Another factor to consider is that most
nutrition experts don’t recommend limiting or restricting entire categories of
foods. It’s also not very easy or practical to do for many dieters. The
individualized nature of this diet also means it would be difficult for
families or groups to try together. Different blood types would require
different eating plans and exercise programs.
The idea of being tied to our ancestors by
tens of thousands of years of blood type evolution can sound very intriguing.
It's easy to understand why people are drawn to this diet; it sounds really
scientific. But there are plenty of smart people who question that science. D'Adamo
has dedicated a section of his website to personally responding to several
critics, pointing out apparent hidden motives for each critic, whether they are
hawking a competing diet book of their own or just against alternative medicine
altogether. There is also plenty of access to D'Adamo's own research on the
While a section on D'Adamo's site labeled
"Independent Scientific Evidence" would go a long way to quiet
critics and help his cause, we really care more about how practical and healthy
the diet plan is. We agree with D'Adamo that dieting is an individualistic
process. But if you are a die-hard carnivore who happens to be blood type A, it
doesn't seem practical to think that you will stick with a diet that eliminates
meat. On the other hand, if you were to cut back a little on meat, follow the
recommended plan, and start to lose weight and feel better, there could be
incentive to make long-term adjustments — science or no science.
Each person is unique, whether because of
their blood type or, more importantly, their personal preferences. Nutritionists
don't recommend cutting out entire groups of foods — that can lead to
unbalanced nutrition and make it harder to stay on the diet for an extended
period. Pay attention to the scientific claims for this diet, given the lack of
independent research. But if you are intrigued, talk to your doctor or a dietitian
to see if the blood type diet is safe for you. They can help you figure out a
practical approach to trying it out. If you get the nod, give yourself a trial
period to see if the plan is effective for you personally.