The Non-Obsessive Way of Eating

Eating Healthy to Live Healthy


Blood Type Diet

Know also as: Blood Group Diet; Genotype Diet;
Type of diet:  Personally tailored from a Nutrigenomics viewpoint; Restrictive guidelines;
Main Benefits: Tailored to the individual’s constitution; Comprehensive diets/ recipes supplied;
Cost: Depending on the recommended diet could be more expensive;
Difficulty: Needs discipline; Unproven by scientific evidence;
Involves Exercise: From intense exercise through to Yoga and Tai Chi dependant on blood group;


What the Advocates Pitch

The Blood Type diet is a personalised diet designed for the individual based on their own ABO blood type. It is a diet derived from Nutrigenomics, a science involving the study of food effects on genes and the understanding of the relationship between nutrition and health. This belief that your blood type reflects your internal chemistry and determines the way you absorb nutrients has been popularised by naturopathic physician Dr. Peter D’Adamo. Naturopathic medicine recognises the biochemical uniqueness of each individual, and that a one-size-fits-all approach does not work. Dr D’Adamo’s research into anthropology, medical history, and genetics led him to conclude that the ABO blood type – A, B, AB, or O – determines a person’s susceptibility to certain illnesses and determines the foods their bodies are best able to digest and absorb. The chemical reaction that occurs between your blood and the food proteins (Lectins) you eat is part of your genetic inheritance, and as blood types are inherited, the claim being that each blood type represents the genetic traits of our ancestors. This includes the diet they evolved on.

The underlying hypothesis is that people with different blood types digest nutrients differently. Lectins, a glue like substance that can attach to the slippery mucosal linings of the body, can affect your blood, and the lining of your digestive tract. If the Lectins in the food that you eat are incompatible with your blood type, and target your organs or body systems, they can begin to interact negatively with the tissues in those areas. Disease is the result. On the other hand, if a person eats food that is compatible, they will be healthier.

Perceived Benefits of this Diet

This way of eating advises individuals to eat according to their blood group so as to improve their health and decrease risk of chronic disease. By eating foods that are compatible with your blood group it is claimed that you can alleviate and improve disorders such as diabetes, hypothyroidism, obsessive-compulsive disorder and enable weight lose. By following a diet that mirrors what your blood type ancestor ate, D’Adamo says adherents will lead a longer, healthier life. This is why it is thought that some people thrive on a vegetarian diet and others on a high-protein one. An aside is that the foods in the diet are all healthy, and because of this, you are bound to experience health benefits if you commit to the dietary changes recommended whether or not the food suits your blood type.

Food that is a part of this woe and food that is not

D’Adamo’s book, Eat Right 4 Your Type (1996), provides a set of blood type specific diets to focus on, and foods that should be avoided, with the recommended food amounts for each type differing greatly.

Type A: The basis of this diet is the “Agrarian” diet associated with the development of agriculture from around 20,000 years ago. People of this type should eat a diet rich in plants and gains along with plenty of fish, and the occasional serving of chicken. All beef, pork, game meats and shellfish are to be avoided as are all dairy products and eggs.

Type B: Called the “Nomad” from the peoples of around 10,000 years ago, this is considered a “balanced omnivore” diet. These blood types have a versatile digestive system that can handle dairy products, red meats, turkey, and fish but not chicken or pork. Grains, green vegetables, and fruits can be added, however, type B should avoid wheat, corn, lentils, tomatoes and seeds of any sort.

Type AB: The mix between types A and B is called the “Enigma”, with the primary focus being seafood, tofu, dairy, vegetables, beans and grains. Fruits like watermelon, figs, and bananas are acceptable. Avoidance of red meat, buckwheat, chicken and corn based products is suggested along with excessive intakes of alcohol and caffeine.

Type O: Considered the oldest form of blood, this “Hunter” version closely resembles the paleo diet. It focuses on high-protein sources, like red meat, seafood, and poultry, certain fruits, and vegetables like spinach and broccoli. This type should gravitate away from wheat, grains and legumes; small quantities of dairy and egg products are allowable.

The Downside and Contrarian Views

The biggest challenge adoptees find with this diet is the restrictive guidelines for each blood type, and the finding of replacements for favoured elements that have been eliminated. However this form of eating is criticised by most health experts on the basis that it encourages followers to eliminate nutritious foods from their diet. While D’Adamo’s hypotheses may sound completely sensible, the opposing view is that lectins in the diet are NOT blood-type specific. Critics maintain that there is no body of proof for any interactions between food proteins and blood molecules that is determined by blood type. Other detractors simply declare that any positive results on the blood type diet is simply due to the fact that the diet happens to be appropriate for your metabolism – and has little to do with your blood type.

Adopting this Type of Eating

This way of eating consists of a strict diet regimen. However what people need most when it comes to adopting this diet is discipline and commitment. The guides written by D’Adamo contain concrete details on food intake and exercise guidelines that leave little room for cheating or excuses. It will take hard work, patience, persistence, and will make your grocery list a bit more specific and expensive.

What does the Scientific Research Say

Research confirms that there is a distinct developmental timeline in ABO blood types over the millennium and there is now strong evidence that people with certain blood types can have a higher or lower risk of some diseases. But at this stage there are no studies showing this to have anything to do with diet. Science does show that certain malignancies can be correlated with the ABO blood groups, for instance, “A” type have about a 20 percent greater risk of developing cancer of the stomach than do group “O” individuals, but the reasons are unclear. One study that found a relationship between blood types and food allergies actually contradicted the Blood Type Diet’s recommendations.

A major 2013 review study, where researchers examined the data from over a thousand studies, concluded that “no evidence currently exists to validate the purported health benefits of Blood Type diets”. Further a PLOS reported research study of 2014, looking at the association between blood type-based dietary patterns and health outcomes, found adherence to certain Blood Type diets was associated with favourable effects on some cardiometabolic risk factors. However these associations were found not to be dependent on an individual’s actual ABO genotype and did not support the Blood Type Diet hypothesis. The same conclusion was reached in a large observational study of 1,455 young adults, eating a type “A” diet (fruits and vegetables) where participants showed improved health markers. However this effect was seen in everyone following the type “A” diet and not just individuals with type “A” blood. Similar results were also found in the latest study carried out in Jan 2016, where no scientific evidence for the Blood Type Diet was supported, other than the fact that the diets recommended for different blood types are relatively healthy in general and would benefit a person of any blood type.

In all, from a scientific standpoint, the amount of evidence supporting the blood type diet is particularly underwhelming. However D’Adamo’s enthusiasm and arguments do hold sway with the general public and it is agreed that he must be doing something right as millions of advocates claim it is one of the most effective weight loss techniques they’ve tried.

Where to get more information

Books: Eat Right 4 Your Type by Dr Peter D’Adamo; The Blood Type Diet Cookbook by Karen Vago;  Blood Type Diet by Valerie Lewis
Facebook: Blood Type Diet; Type A Blood Diet; Blood Type Diet and Exercises for Healthy Joints;
Well Know Advocates: Cheryl Cole; Miranda Kerr; Kate Upton; Jason Lee; Demi Moore;
Websites: ; ; ;

Sources for this Guide:
Wang J, García-Bailo B, Nielsen DE, El-Sohemy A (2014) ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors. PLoS ONE 9(1): e84749.