Blood Group Diet: Operation, Menus & Notice

[Article updated on 19/09/2023]

The blood type diet is based on the principle that each blood type must follow a specific diet. Depending on whether it belongs to group 0, A, B or AB, in fact, the immune system reacts positively to certain foods and is intolerant to others. The right diet must therefore take blood type into account, include certain foods and exclude others. But, is it true? Is a hemodiet a correct diet and, above all, does it have a scientific basis? Learn all about the blood type diet with my guide.

Before reading on

I’m not an expert in this field, but I am passionate about nutrition and health.

The articles you’ll find on my site are the result of in-depth research that I’d like to share with you. However, I would like to stress that I am not a health professional and that my advice should in no way replace that of a qualified physician. I’m here to guide you, but it’s important that you consult a professional for specific questions or medical concerns. Your well-being is important. So be sure to consult the appropriate experts and take the best possible care of yourself.

Blood group diet: what is it?

The blood group diet or hemodiet is a style of eating according to which each person must choose foods according to their blood group: A, B, 0 or AB. This diet was developed by the American naturopath Peter d’Adamo. In fact, the latter continued and developed the work of his father, James d’Adamo.

Peter J. d'Adamo
Peter d’Adamo is the originator of the blood group diet.

According to this diet, there is a correlation between diet and the immune system. The blood is the expression of the immune system and dietary habits are the factor that most affects this system. For the diet to meet the needs of each individual and be adapted to their specific strengths and weaknesses, it must therefore take into account their blood group and characteristics.


The first to theorize the existence of a relationship between diet and the immune system was James d’Adamo in 1957. The American doctor observed that patients with different blood types reacted differently to the same diet. This led him to believe that their different needs were linked to a specific biological characteristic. He then developed diet plans based on blood types for his patients. As the method seemed to work, he continued to refine it based on his observations, which he outlined in the book “One Man’s Food,” published in 1980.

Following in his father’s footsteps, naturopath Peter d’Adamo decided to deepen his research to understand if there was a link between diseases and blood groups. The results of his studies were merged into the book “Eat Right 4 Your Type” published in 1996.

Blood group diet: the principles

The blood group diet is based on the ABO blood classification system, which divides blood into 4 categories (A, B, AB, 0) based on the presence or absence of A and B antigens.

Different blood types appeared in human evolutionary history at different times. According to D’Adamo, they would therefore reflect the type of diet that our ancestors followed at that time. Specifically, Group 0 would be the oldest group, typical of Cro-Magnon men, who ate mostly meat and fewer vegetables.

It was during the Neolithic period that group A developed. It would be the expression of the first major change in man’s way of life: from nomadic to sedentary. In Asia and the Middle East, this change gave rise to the first crops, notably fruits and vegetables, which thus became the basis of the diet of the people of the time.

The group B gene would rather have appeared in populations of nomads who settled in the mountainous regions of Asia 10,000 years ago. These peoples were mainly devoted to pastoralism and ate mainly meat and dairy products.

The AB group, finally, would be the most recent. Its appearance dates back 1000-1200 years. At that time the Roman Empire was invaded by barbarians and type A blood was mixed with type B. This blood group, according to d’Adamo, would have inherited the tolerances of the two original groups but without their antibodies . This would make him both resilient and vulnerable.

Blood taken
The first step to following a blood type diet is knowing your blood type.

The blood group 0 diet

What to eat

To stay healthy, those belonging to group 0 need a diet rich in animal proteins, which their digestive system can tolerate without difficulty, vegetables and legumes. The important thing is the intake of iodine contained in fish and algae. This mineral stimulates the production of thyroid hormones. Iodine is therefore useful for group 0, which has a tendency to hypothyroidism. Furthermore, this protein diet acts like a powerful appetite suppressant and keeps its followers satiated for a long time.

Typical DayBreakfastLunchDinner
Mondaychickpeas or cannelloni beans with tuna or mackerelRice salad with boiled egg + turkey meat + olives + parsley + grated carrotsRoast lamb with spinach
Tuesdayscrambled eggs with sweet potatoes + chicory coffeesoup without potatoes + rice or millet + chicken breastgrilled red meats (beef, veal, horse) with artichokes or broccoli or chard
Wednesdayrice or buckwheat pancakes with oil or almond butter and green teagrilled cod with asparagus or beets and white ricewhite meat (chicken or turkey), chickpeas and escarole or zucchini
THURSDAYGrilled chicken or turkey with herbs or ribs and a little quinoascrambled eggs + herbs + ribs + spinach + a little buckwheatbean puree with endive + grilled calf’s liver
FridayBuckwheat bread and oil with unsweetened chicory coffeesalmon with celery + pine nuts + lemon and chicoryBoiled sweet potatoes + perch or sole + arugula
SATURDAYprunes + 5-6 almondswhite or brown rice with zucchini and perchbeef or veal stew with peas, carrots, onions and celery
Sundayquinoa with seasonal vegetablesgrilled veal with chicoryperch or sole or cod + arugula
Special menu table and recipes for the blood group O diet

What to avoid

The number 1 enemy of people belonging to group 0 is gluten. They should avoid it because its interference with metabolism weakens insulin activity. It is the main cause of weight gain and increased risk of diseases like diabetes. Certain legumes like lentils and Spanish beans should also be avoided because their lectins weaken muscle tissue’s ability to store energy.

The blood group A diet

What to eat

In the blood group A diet, foods of plant origin such as vegetables, fruits and legumes are particularly important, but also fish and eggs. Meat, particularly red meat, is a food that is not recommended. Among cereals, those that do not contain gluten are recommended. In general, the diet of group A should be based on natural and fresh foods, possibly not contaminated with pesticides or preservatives.

Typical DayBreakfastLunchSnackDinner
Mondaygreen tea, fruit + soy + pumpkin seed yogurtbrown rice with zucchini and salmon + mixed salad5-6 almonds or other nutsboiled chicory and grilled turkey
Tuesdayalmond milk, a fried egg + 1-2 fruitsbean soup, boiled broccoli and mackerel3-4 nuts or other dried fruitsraw cod with lemon and raw fennel
Wednesday4-5 cookies and a piece of fruitred radish + roast chicken with onions and carrotsa handful of pumpkin seedspoached egg with onions + carrots and zucchini
THURSDAYcoffee, dark chocolate, 4-5 almonds and a hard-boiled eggred rice with asparagus and mackerel + mixed saladsoy yogurt + hemp seedsgrilled tuna (lightly cooked) and mixed salad
Fridaysoy milk, a piece of Castagniccia and 3-4 nutsgrilled swordfish with lemon + mixed salad and pineapple2-3 dried figs and a few almondschicken broth and steamed cabbage
SATURDAYchicory coffee, fried egg and cannelloni beanslentils, chicken breast with mushrooms and boiled spinacha handful of pumpkin seedsminestrone with seasonal vegetables (without potatoes or tomatoes)
SundayHerbal tea + rice cakes with peanut (or almond) butterbaked (or boiled) chestnuts + boiled chicory and fried egg1-2 dried plums (with pit)raw salmon with lemon and chard
Special menu table and recipes for the blood group A diet

What to avoid

The two foods to avoid are red meat and dairy, which are the two main causes of weight gain. They sabotage the effect powerful fat burner other foods. Concretely, red meat that the body cannot assimilate well is stored in the form of fat. Poorly tolerated by the body of people with blood group A, dairy products and cheeses can slow down the metabolism. They are high in saturated fats. This increases the risk of heart disease, diseases to which those belonging to group A are particularly predisposed.

blood type diet
The blood group diet recommends consuming organic fruits and vegetables preferably.

The blood group B diet

What to eat

According to Dr. James d’Adamo, the Group B diet includes “the best of the animal and plant kingdoms.” This group whose digestive system adapts well to changes can follow a balanced diet, with a wide variety of foods. Cheese, liver, eggs, meat and green vegetables are useful foods because they help balance metabolism.

Typical DayBreakfastLunchDinner
Mondaytwo slices of bread or 2 rusks with honey or jam + a glass of milk or a pot of yogurtsalad of mixed vegetables, 70 g of ricotta ravioli with a spoonful of cream + 1 fruit2 hard-boiled eggs, 1/2 full sandwich + potato and leek soup + lettuce and arugula salad.
Tuesday50g of whole grains + freshly squeezed fruit artichoke + mixed salad with lettuce + 1 whole sandwich + 1 radish + 50 g parmesan shavings + 1 fruit160g beef burger, a thin slice, 1 wholemeal bun + steamed vegetables
Wednesday30g cereal flakes + 1 low-fat yogurt with honey + 1 cup of tea.vegetable salad + 1 fresh fruit + 70 g of wholemeal penne with cream + 30g of cooked hamred radish salad + 220 g mackerel gratin + 1 whole sandwich.
THURSDAYfresh fruit smoothie with semi-skimmed milk.lettuce salad + cucumbers + arugula + 150 g veal escalopes in milk + boiled corn with 1 teaspoon of extra virgin olive oil + 1/2 full sandwich4-5 wholemeal rusks + 200g cream of mixed legumes (beans, lentils, peas, chickpeas) + 50g fat-free raw ham
Fridaymacchiato or barley with a little honey + 30g mixed cerealsunlimited grilled vegetables + 1 cuttlefish with marinara + 1 whole sandwich + 1 fresh fruit.50g lean cooked ham + 60g spinach + carrots + cow’s milk ricotta + sautéed zucchini with herbs + 1 complete sandwich.
SATURDAYtea or coffee, 1 low-fat yogurt with a little honey, 2 wholemeal biscuits with a little orange marmalademixed steamed vegetables + 30g bread + 100g grilled beefzucchini and steamed potatoes + 100g of skimmed raw ham.
Sundaymacchiato or barley with a little honey, 30g mixed cereals200g fish, grilled peppers with a little oil + wholemeal bread + 1 fruit150 g of fennel and carrots + 200 g of low-fat cooked ham + wholemeal bread
Special menu table and recipes for the blood group B diet

What to avoid

Like those in group 0, people in group B are intolerant to wheat gluten. They also tend to gain weight with certain foods such as lentils, buckwheat, peanuts, sesame and corn. In them, these foods can negatively affect metabolism, causing hypoglycemia, fatigue and water retention.

The AB blood type diet

What to eat

The digestive system of group AB has a fairly high general tolerance towards all food groups, although it has intolerances typical of group A and group B, from which it derives.

Typical DayBreakfastLunchDinner
MondayGrilled turkey with sweet potatoes and coffeeCod with cauliflower and other cooked vegetableslentils + celery + carrots + onions + some potatoes
Tuesdayrice cakes with almond butter and green teamillet with zucchini, onions and tunahake with baked potatoes and parsley
Wednesdaya hard-boiled egg + grapefruit juice + coffeeturkey breast with red beets, onions and zucchinigoat cheese with chard and rye bread
THURSDAYlean ricotta with chestnut honey and coffeebread + meat + potatoes + tuna and poached eggshard-boiled eggs with peas and spinach
Fridayboiled oatmeal + soy milk + nutsscrambled eggs with cooked crushed tomatoesnatural mackerel with mixed salad and quinoa
SATURDAYToasted rye bread with peanut butter + lightly sweetened green tea or barley coffeewhite rice salad with carrots, zucchini, celery, green olives, parsley, basil, mozzarellabean purée with chicory or cooked endive and tofu
Sundayomelette with unsweetened plum jam + green tea or barley coffeepotato gnocchi and goat cheesetuna minestrone
Special menu table and recipes for the AB blood group diet

What to avoid

Those belonging to group AB have the low acidity of group A, which makes it difficult for them to digest red meat. This group also has the same intolerances as group B towards corn, buckwheat, sesame, runner beans and wheat, which reduce the effectiveness of insulin. Lentils and peanuts, on the other hand, are well tolerated.

The advantages of the blood type diet

According to followers of this diet, eat according to your blood type:

  • promotes gastrointestinal health; this results in better digestion, better intestinal rhythm and reduced stomach acid;
  • stabilizes blood sugar levels and thus prevents the development of excess weight, insulin resistance and diabetes;
  • improves the ability to concentrate;
  • allows the patient to achieve greater general well-being.

Disadvantages of the blood group diet

Although the blood type diet has gained popularity in recent years, it is important to keep in mind that there is a lack of evidence supporting its claimed benefits. The diet can be restrictive and can be expensive. Additionally, it can be extremely time-consuming to prepare meals from the food lists provided. There have been no rigorous scientific studies on the blood type diet. As with any diet or exercise program, it is important to speak with a doctor before starting this regimen.

Is the blood type diet effective?

The blood type diet lacks solid scientific evidence because the studies conducted are limited. These studies have not determined that the overall weight improvement or loss people experience is due to the direct relationship between what they eat and their blood type.

In 2014, Canadian researchers from the University of Toronto published a study. This study shows that people’s nutritional needs do not vary based on their blood type. It is therefore not necessary to restrict the consumption of certain foods just because you have blood type A, B or O blood.

Additionally, it is not proven that this type of diet improves digestion or provides more energy. Being a fairly restrictive diet in terms of choice of foods, maintaining it over time is therefore not easy. For this reason, it is only recommended if you want to lose weight or control a specific disease. You should eat a balanced and healthy diet and consult a nutritionist or health professional, so that they can formulate a nutritional plan tailored to your needs.


It’s all about the goal. Thirty to forty-five days is enough if you only have 3 to 5 kilograms of excess weight to lose. On the other hand, it will take more time to lose weight more pronouncedly.

Blood group diet: what to eat?

Depending on the blood group diet, for each group there are foods that are more or less compatible with the immune system. Note that the immune system is the sentinel of our body and has its main seat in the digestive system. According to the designers of this diet, the immune system only recognizes and accepts certain foods. But other foods can trigger dysfunction and even chronic inflammation. This inflammation can cause headaches, lead to weight gain, increase cholesterol levels and blood pressure, or lead to actual illness.

General rules common to all groups

In addition to foods to eat and avoid, sample weekly menus are provided for each group. Eating habits do not take into account the seasonality of foods. These menus therefore do not have to be followed to the letter but give you ideas for building your own menu based on the specificity of your blood group. Then there are general indications common to all groups:

  • At least half an hour before breakfast, drink a cup of lukewarm water.
  • At lunch, do not weigh food or count calories but eat without excess.
  • Avoid eating carbs at dinner unless you plan to exercise right afterward.
  • Eat seasonal fruits and vegetables, preferably organic.
  • Prefer foods that are possibly gluten-free.

Opinion of health professionals on the blood type diet

The different diet models proposed by Dr Peter d’Adamo are not magical. These are protocols based on the paleo and vegetarian diets. They are full of prohibitions and recommendations that have nothing scientific in them. Rather, these models contribute to giving the impression of a structured and solid system, which puts the patient in a position of control and strength. Adherence to the diet itself is easier.

But these are unbalanced models. They involve completely arbitrary eliminations and reinforce the wrong idea that there are good and bad foods. The fact that an employed and sedentary person lost weight thanks to these protocols certainly does not testify to their scientific value. Rather, it indicates that greater attention to what is consumed can only do good.

In the end, the blood type diet is nothing more than yet another fad diet. Behind a barrier of pseudoscience and more or less arbitrary prohibitions, this regime can obtain good results. And he owes these good things to the oldest trick in the world: eat less, eat fresh and choose your food carefully. Evolution and blood groups have nothing to do with it. They are just the icing on the cake.

User reviews on the blood type diet

Some users have not found satisfaction eating according to their blood type. On the other hand, the majority of followers of the hemodiete are fully satisfied. This is among others the case of Emma Jml. She claims that the blood type diet works 9 times out of 10. She says she lost around 3 kilograms of weight in less than 2 weeks. Emma is especially delighted to have found the solution to her digestive problems (constipation, absence of burps, etc.).

Bérengère, another fan of the blood group diet, is so convinced of the effectiveness of the method that she reads selected parts of the book “4 blood groups, 4 diets” by Dr. Peter D’Adamo.