Our blood can tell us a lot about our health—how well our organs are working, diagnosing diseases and conditions and finding out certain risk factors. But could our blood also indicate what type of foods we should be eating to stay healthy?
Naturopathic physician Dr. Peter J. D’Adamo thinks so. According to D’Adamo, everyone’s blood type is a unique cellular fingerprint that determines everything from an individual’s predisposition to illness to which foods to eat and even how to exercise. His theory was published in 1996 and became a New York Times bestseller, birthing millions of devotees.
“Oftentimes, trendy diets come up with ‘one-size-fits-all’ programs, providing the same recommendations for everyone,” said Jennifer Oikarinen, a registered dietitian at Banner - University Medical Center Phoenix. “In contrast, the blood type diet offered a different and distinct set of guidelines that appealed to many people—hence its popularity.”
Blood type diet: Innovative diet or science fiction?
While it’s tailored very specifically to those O, A, B and AB and seems like a no-brainer, is the blood type diet legit—and has it been proven to actually work?
“Simply put: No,” Oikarinen said. “The blood type diet is based solely on observations made by the author. Results and claims regarding the diet have not been measured or proven to be successful in a clinical trial or research study.”
Dr. D’Adamo hadn’t produced his own research, so independent researchers decided to take it upon themselves to evaluate the diet, and 2013 and 2014 studies found no evidence to suggest any benefit or claims associated with a person’s blood type.
Though each blood type has a different set of "rules" for what to eat and what not to eat, each one focuses primarily on lean proteins and fruits and vegetables to varying degrees, which are well-known recommendations for health and weight loss. For that reason, this type of diet could potentially help an individual lose weight.
“By increasing the number of servings of fruits and vegetables consumed, you could absolutely improve your health and wellness, thereby seeing a multitude of benefits,” Oikarinen said. “But it may have nothing to do with your blood type.”
How the blood type diet works
Here’s a breakdown according to the “Eat Right for Your Type” diet:
- Type O: A high-protein blood type that focuses on lean proteins and certain vegetables and fruits but avoids certain grains, dairy and legumes.
- Type A: A plant-based blood type that focuses mostly on fresh and organic fruit and vegetables and whole grains.
- Type B: A nomadic blood type that focuses on mostly plants and meats but avoids chicken, pork, wheat, corn, lentils and tomatoes.
- Type AB: An enigmatic blood type that resembles a pescatarian diet, this diet focuses on mostly fish and seafood, fruits and vegetables, whole grains and dairy but avoids meat or poultry.
The downsides of the blood type diet
Sounds like healthy eating, right? While this may be true, the blood type diet is very specific, and therefore is quite restrictive. It doesn’t take into account personal preferences.
“For example, if you're Type A blood and enjoy eating meat and other animal proteins, you won't be too pleased to find out your blood diet is supposed to eat a vegetarian-based diet of fruits and vegetables, beans and whole grains,” Oikarinen said. “It could also affect your wallet since the author recommends buying organic.”
Eat this not that
There’s no proof that your blood type drives what you should eat, but there’s also little proof that the blood type diet is harmful if you ensure you’re getting a healthy balance of necessary nutrients. That said, maybe forgo the diet books and fad diets, and instead focus on making a couple small changes to your current diet. The best diet is always one that is balanced and fits into your lifestyle.
“Think about how you can make each meal just a little better; add protein, fruits and veggies, drink more water, eat slower, eat less processed food—do whatever works for you,” Oikarinen said. “For example, if your usual breakfast is a vanilla latte and cheese Danish, try replacing the Danish with a whole grain muffin. As an extra bonus, grab a yogurt for a boost of protein.”
If you’re considering the blood type diet or any major changes to your current diet for weight loss or overall health, talk to your doctor or a registered dietitian first. To find a specialist near you, visit bannerhealth.com.
For other healthy tips, check out:
- What to Know About the Flexitarian Diet
- Veganuary: 7 Things to Know Before Eating Vegan for a Month
- Get the Skinny on Fats: The Good, the Bad and the Worst for You