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What Is the Blood Type Diet? (And Does It Actually Work?)

You may not have to cut out carbs to lose weight.


Eat Right 4 Your Type, the mega-bestselling book that recommends tailoring your diet to your blood type, was ahead of its time. Prior to 1996 — the year it was published — blood type was information used almost exclusively in the event of an emergency transfusion. The idea that blood type could (and should) play a key role in weight loss or guide nutrition decisions was dismissed by the majority of the medical doctors. Nonetheless, the program that the book espoused (known as the “blood type diet”), remains — nearly three decades later — a global phenomenon that’s been translated into 65 languages.

“Individuals are different, and therefore a diversity of diets makes sense,” says Peter D’Adamo, ND, a natural-health expert and researcher who helped pioneer the approach. “If you eat right for your blood type, you will lose weight. The science is clear — and so are the testimonials from hundreds of thousands of people who have shared their success stories.” Keep reading to learn more about the blood type diet and its effectiveness for weight loss.

What is the blood type diet?

The concept of personalized nutrition has renewed discussions about the blood type diet both on social media and among medical experts. Doctors are returning to the diet’s original claims, and examining it through the lens of modern science. Among those who tout its merits is orthopedist Emily Woolcock, MD, who says she lost substantial weight and relieved fatigue and pain by following the blood type diet. “It even helped with my carb cravings,” she says.

So what’s the secret to its success? According to Leslie Sharpe, MD, the blood type diet is an anti-inflammatory diet at its core; “an approach proven to help every type of dieter slim down,” she explains. Dr. Sharpe used the plan to shed menopausal weight and boost energy while working 24-hour shifts in the emergency room.

How does the blood type diet work?

The plan’s premise is fairly simple: Each of the different blood types evolved to view the lectins (or proteins) in various foods as either welcomed guests or invaders. When we eat foods compatible with our blood type, digestion proceeds smoothly — delivering slimming nutrients and releasing hormones that support a healthy metabolism. Conversely, when we eat incompatible foods, lectins get stuck. “The lectins attach to the walls of the digestive tract and can initiate inflammation,” Dr. D’Adamo explains. The result is cellular “clumping, an effect that mimics allergies and may cause leaky gut, IBS, and weight gain.

What foods should I eat according to my blood type?

Building on this science, researchers observed the impact of thousands of foods on various blood types, with the goal of establishing the optimal diet for each. “I was amazed to see the correlations,” says functional diagnostic nutrition practitioner Jennifer Woodward, who found that the research substantiated results from numerous food sensitivity tests she’d administered. One example: Type O’s should avoid wheat and dairy. “It makes me think that paying hundreds of dollars for a food sensitivity test is an unnecessary expense if one simply knows their blood type,” she says.

The blood type diet has, of course, evolved since its introduction in 1996. According to naturopath Samm Pryce, ND, who studied under Dr. D’Adamo and now teaches patients a multilayered blood type diet system, it’s far more precise. While there are still food plans for each of the four types, there’s also customization for the individual.

Another change in plan: Carbs aren’t the enemy. “Types A, B, and AB, who make up more than half of the population, can digest grains easily, and therefore, carbs don’t get in the way of weight loss,” explains Dr. Pryce.

In fact, type A’s and AB’s may actually need more carbs — 2.5 times more — to lose than many diets prescribe, according to Dr. D’Adamo’s research. “Women do best on a wider variety of smart carbs than strict keto recommends,” Dr. D’Adamo says.

Dr. Pryce notes that when we eat according to our blood type, weight loss is far more likely. Below is the plan she calls one of her “secret weapons for living a long and vital life!”

What diet plan works best for my blood type?

Dr. D’Adamo says that our genes hold a “memory” for foods eaten by our earliest ancestors. To spark slimming, his plan advises matching your blood type with a personalized food code:

  • Type O (Carnivore): The oldest blood type, these hunter-gatherers gain energy when they consume a diet that’s rich in animal proteins and low in gluten. (Think: modified keto or Paleo plans.)
  • Type A (Plant-Powered): As their early ancestors evolved to live on farms, this group learned to thrive on cultivated fruits, vegetables, and complex grains. (Think: semi-vegetarian lifestyles.)
  • Type B (Omnivore): When people started migrating between different climates and terrain they became masters of food flexibility, able to rev their metabolism on a variety of fare. (Think: balanced macro plans.)
  • Type AB (Hybrid): Unlike the other types, which are determined by taking the dominant blood type from their parents, this rare and “mysterious” group borrows certain traits from an intermingling of A and B types, so their food intake is a mixed bag. (Read: everything in moderation.)

Don’t know your blood type? Call your doctor to find out or conduct your own quick test with an at-home kit.

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.

This article originally appeared on our sister site, First for Women.

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