A very popular diet that’s been making the rounds since 1996 is the Blood Type Diet. Invented by Peter D’Adamo, a naturopathic physician, it was first published in his book of the same name.
The blood type diet quickly took off, and today people still follow its guidelines. The theory behind this diet is that it claims to tell you exactly what you should be eating (and not eating) depending on your blood type (or ABO genotype). And some say it helps them lose weight.
But is there any scientific evidence or risk factors? Is centering your eating habits around your blood group legit? Or is it just another fad diet like the low-carbohydrate diet?
The Theory Behind the Blood Type Diet Plan
The idea behind the blood type diet plan is that your ABO genotype (blood type) influences many areas of your health.
Your blood type may tell you how your body reacts to food. It may also tell you about your vulnerability to stress and disease, and how to control weight gain.
Research suggests certain blood types may be prone to different illnesses. Independent studies have shown:
- That those with blood types A, B or AB may have an increased risk factor for high blood pressure and heart disease.1
- That blood groups B and AB may have a greater risk of certain bacterias.2
- That blood type O could have a higher risk for developing stomach ulcers.3
The blood type diet believes when red blood cells, white blood cells, and platelets come in contact with certain food components (including lectins)… a chemical reaction occurs. This could cause hormonal disruptions, and many resulting health issues.
So, the theory is, if you know what foods your blood type doesn’t agree with, you can avoid such issues.4
How to Eat (and exercise) for Your Blood Group
According to Dr. D’Adamo, this is how you should eat and exercise for your specific blood type:5
Please note that Dr. D’Adamo’s findings are often in contradiction to Dr. Gundry’s findings, meaning the Blood Type Diet may not be ideal for most people. Dr. Gundry believes excess animal proteins, A1 dairy, grains, non-pressure cooked legumes, and sugar should be avoided, period, no matter your blood type.
Type O Blood
Type O-blood types should focus on a low-carbohydrate, high-protein diet. That means lots of meat – as well as fish, fruits and vegetables.
Limit grains (they’re sensitive to gluten), dairy products, legumes, and cabbage. This diet very much resembles a low-carb, paleo diet, and flies against Dr. Gundry’s teaching when it comes to animal protein intake.
Type O’s are also the most sensitive to food allergies. Their exercise routine should focus on high-intensity aerobic exercise, contact sports, and running.
O-blood types are said to be able to digest meat better than other blood types. O-blood types have greater levels of a certain enzyme in the digestive tract. This enzyme allows better metabolization of meat. It also allows being able to heal the digestive tract.
Type A Blood
The type A diet is very much a plant-based diet. A-blood types should, at the very least, limit red meats. The diet is still high-protein. But protein sources should be tofu, seafood, fruits, vegetables, turkey, and whole grains. Dairy products, wheat, corn, and kidney beans should be avoided on a type A diet.
Again this is different from Dr. Gundry’s philosophy, especially when it comes to tofu.
If you’re following a type A plant-based diet you may benefit from calming, centered exercise routines – such as yoga or tai chi. As well as meditation.
Type B Blood
According to the blood type diet, type B-blood types are said to have strong immune systems. B types may also have very tolerant digestive systems. They can eat a diverse diet that includes meat, fruits, dairy products, seafood, and grains.
If they’re struggling with weight gain, they should avoid chicken. Also avoid corn, peanuts, lentils, tomatoes, and wheat to assist with weight loss.
Type B’s should embrace moderate exercise that provides a good mental balance. Such exercises are hiking, cycling, tennis, and swimming.
Type AB Blood
Type AB-blood types mix blood types A and B… They should focus their intake on dairy, tofu, lamb, fish, grains, fruit, and vegetables. For weight loss, they should limit chicken, corn, buckwheat, and kidney beans.
They should also limit caffeine and alcohol. It’s recommended they eat smaller, more frequent meals. This is to counteract issues caused by insufficient stomach acid.
As a combination of blood types A and B, exercise should follow both blood types.
Is There any Evidence that This Diet Works?
There is no solid scientific evidence published on the blood test diet.6
In 2004, one study found improvements concerning cardiometabolic risk factors. This was specific to those following the diet. For example:
- The Type A diet was associated with lower BMI. It was also associated with waist circumference, blood pressure, and serum cholesterol levels.
- The Type AB diet was associated with similar results. But, it wasn’t associated with BMI and waist circumference.
- The Type O diet was associated with lower triglyceride levels. But it wasn’t associated with BMI and waist circumference.
But, these dietary improvements could not be linked specifically to the ABO genotype. That is, “blood type.” 7
Blood Type Diet – Fad Diet or No?
The blood type diet does have some elements in common with Dr. Gundry’s program.
But also, there are a large number of foods encouraged on the blood type diet that Dr. Gundry believes you should never eat.
According to The Blood type diet, focussing on plant-based, high-protein diets is key. Limit meat consumption (except for the O-blood type). An awareness of how lectins can disrupt your hormones is also important.
While Dr. Gundry certainly agrees with the lectin aspect of the blood type diet, he is NOT a huge proponent of a high protein plan — especially when the protein comes from animal sources like meat and dairy. High protein vegetables are a better choice.
The bottom line? You should talk to your doctor about whether it’s the right choice for your personal health. Also learn for yourself about the food that you eat, by asking questions like, are acai bowls healthy?
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