Women Over 50 (Some Who Are Doctors Themselves) Are Losing Weight With The Blood Type Diet — Could It Work For You?

Plenty of companies these days are promising to harness the power of your individual DNA to gain insights into your health. In fact, personalized nutrition plans seem to be all the rage. But aside from any pricey tests, you likely already know a key piece of your DNA picture that can help you crack the code to weight loss: your blood type. For three decades, a group of nutritionists have maintained that your blood type can predict what foods your body can process with ease — and what foods causes it problems. And millions of women have reached their happy weight following the blood type diet’s guidelines. But what is the science behind it — and can it work for you? We went to the experts to find out all you need to know.

What is the blood type diet?

Eat Right 4 Your Type, the mega-bestselling book that recommends tailoring your diet to your blood type, was ahead of its time when it came out in 1996. Prior to that year, blood type was information used almost exclusively in the event of an emergency transfusion. The majority of doctors dismissed the idea that blood type could (and should) play a key role in weight loss or guide nutrition decisions. Nonetheless, the program 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.

The blood type diet is rooted, quite literally, in ancient history: It turns on the way different populations of our early ancestors favored the foods that were readily available in their particular environments. 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 familiar friends or foreign 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 sort of 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. (Click here to discover how the JJ Virgin diet can help heal leaky gut.)

Building on that science, researchers observed the impact of thousands of foods mingling with various blood types under microscopes. Their goal was to establish the optimal diet for each blood type.

One discovery: Carbs don’t have to be the enemy

Under those microscopes, scientists found that not all blood types have to avoid carbs. “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 naturopath Samm Pryce, ND, who studied under Dr. D’Adamo. In fact, type A’s and AB’s may actually need more carbs — 2.5 times more — to lose weight 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,” he says.

Why the blood type diet makes so much sense

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 stressful 24-hour shifts in the emergency room.

“I was amazed to see the correlations,” says functional diagnostic nutrition practitioner Jennifer Woodward, MS, 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. (Curious about your own food sensitivities? You can save money with one of these at-home food sensitivity test.)

Fans rave about the blood type diet’s success rate

The reason for the plan’s staying power all these years: It works. Dr. D’Adamo says, “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.”

In fact, doctors today are returning to the diet’s original claims after examining it through the lens of modern science and seeing the concept still holds up. 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.

The diet continues to evolve and improve itself

The blood type diet has, of course, evolved since its introduction in 1996. According to Dr. Pryce, who 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.

There’s even good news for people who tried the blood type diet years ago and found that it didn’t work for them. Dr. Pryce explains we now know that 20% of people are “non-secretors,” meaning they don’t secrete blood antigens into their saliva and digestive juices, and thus “defy” their blood type. They’re also more likely to carry candida yeast, which sabotages slimming. Your doctor can test your status or you can get an at-home Secretor Status Collection Kit (Buy at 4yourtype, $109.95).

Discover what works best for your blood type

Here, how the blood type diet can work for you. If you know your type, scroll down to that section for the details. Don’t know your blood type? Call your doctor to find out or conduct your own quick test with an at-home kit (Buy on Amazon, $14.99).

If you’re Type O: You’re a carnivore

About 44% of the human population is type O. 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. (Click through to learn more about the carnivore diet for weight loss and to see amazing carnivore diet before and afters.)

Beneficial foods for type O: kale and broccoli, omega-3–rich flaxseed oil and fish lower inflammation; red meat (especially beef and bison) builds muscle.

Foods to avoid: inflammation triggers like wheat, corn, dairy, lentils and peanut oil; and thyroid disruptors like cauliflower and cabbage. Find more about Type O here.

If you’re Type A: You’re plant-powered

About 42% of the population has type A Blood. 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.)

Beneficial foods for type A: Soy, snapper, sardines and peanuts are good protein choices; escarole, fava beans, silver dollar mushrooms and prunes boost the microbiome; lemons and blueberries help to thin A’s naturally thicker blood.

Foods to avoid: hard-to-digest proteins like most meat, shellfish, pork and high-fat cheeses; vinegar that irritates the stomach; foods that drive bacterial overgrowth like potatoes, kidney beans and lima beans. Find out more about Type A here.

(Click through for one of our favorite plant-based diets for weight loss.)

If you’re type B: You’re an omnivore

Between 10 and 12% of the population is type B. 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.)

Beneficial foods for type B: muscle-building lamb, sardines and cod; liver-boosting beet greens; lectin-sensitivity blocking feta, ricotta and cottage cheese; plus whey, broccoli, pineapple and grapes.

Foods to avoid: chicken, corn, soy, sesame seeds, buckwheat, wheat, rye; liver-taxers like lentils, black beans and artichokes; gut irritants like peanuts and tomatoes. Learn more about type B here.

(Click through to discover the Glucose Goddesses best hacks to keep blood sugar in check.)

If you’re type AB: You’re a hybrid

Just 2 to 4% of the population is type AB. Unlike the other types, which are determined by taking the dominant blood type from their parents, this rare group borrows certain traits from an intermingling of A and B types, so their food intake is a mixed bag. (Read: everything in moderation.)

Beneficial foods for type B: muscle builders like turkey, cod, tuna, salmon and tofu; gut strengtheners including portobello and silver dollar mushrooms; eggplant, cranberries, watermelon and walnut oil to enhance cell signaling; plus brown rice, cucumber, oatmeal, eggs and miso.

Foods to avoid: red meat, chicken, corn, lima beans, black beans and sunflower seeds, which trigger lectin sensitivity; gut-overgrowth triggers of sucrose, bananas, oranges; adzuki beans; and system-stressing coffee. Learn more about type AB here.

(Click through to discover the power of morning protein for weight loss.)

Success story: Debbie Kasadine, 61, Type O

Standing against a wall, all eyes on her, Debbie Kasadine found herself at her first weight-loss meeting at the age of 8. What followed was decades of diets: the popcorn diet, the cabbage soup diet, the ultra-low-carb diet… Each one left her body weak, her hair flimsy and her hopes dashed. The Missouri native lamented, Nothing ever works after the first week.

Then while cleaning a private library one day as a professional housekeeper, Debbie’s duster crossed the path of a book called Eat Right 4 Your Type. Debbie flipped to her section and was amazed to discover that she could eat lots of satisfying protein and fats. “The chapter gave me so much information I’d never heard before,” she recalls. “It was like sitting in a dark room and someone turned on the lights.”

After five days of eating according to her O type, Debbie was 6 pounds lighter. She kept avoiding dairy, peanuts, pork and avocado, which didn’t support her system. Instead she nourished herself on beef, fish, veggies and sprouted grain bread. “It was so easy.”

Skip ahead 2 years, Debbie was 115 pounds lighter and could slip into single-digit sizes! She even went through menopause symptom- free. Her doctor said, “I’ve never seen this before!” Bonus: Debbie has maintained her weight loss for years. “It’s about feeling great and having the best life you can in the body you live in!”

Success story: Terrell Salley-Holliman, 57, Type B

With the smell of sweet cinnamon rolls wafting through the shopping area, Terrell Salley-Holliman knew she couldn’t get into her car without buying two buns for herself. Cinnabon is my food kryptonite, she admitted to herself.

Over the years this self-described “sugar fiend” watched her body become so inflamed from lupus and excess weight that she couldn’t get out of bed. Doctors warned she would die if things didn’t improve. Desperate for relief, Terrell managed to lose some weight at the gym and while watching her portions. But she didn’t reach optimal health until she started implementing the blood type plan. She realized, “Unlike age, weight or metabolism your blood type doesn’t change. It is your DNA!”

Following advice for her Type-B body, Terrell reached for whole foods like beets, cabbage and mushrooms. She satisfied her sweet tooth with fruit, teas and navy bean pie. And she carried baby carrots in her bag for snacks. Next, she cut out chicken, which she learned was “poison” for her system. She noticed, “My bloat and brain fog disappeared and my weight dropped dramatically.” In all, Terrell has maintained her 100-pound loss and reversed her lupus! (Her husband followed his type’s plan and lost 65 pounds.) So impressed, Terrell became a health educator in New Jersey, leading women to customize their eating. (Find her on Instagram @Terrell_llyw or check out her new book.) Now seven sizes slimmer, she says, “Having the right personalized foundation changes everything!”

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A version of this article originally appeared in our print magazine, First for Women.

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

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