Should your eating habits follow a specific plan according to your blood type?
Diets. We’ve all heard of them. Most of us have laboured through committing to one at some time or another. How much of what is promised holds enough truth and delivers the healthy results we crave? There’s a constant push and pull effect between fact and fad. Science is the key determining factor for many. Can it be proved that a specific theory actually works? A diet that delivers results for one may not appear all that effective for another, no matter how strictly “the rules” of the diet were kept.
For two decades, the blood type diet has been just one of many nutrition plans to cause a little controversy. Differing opinions from a variety of industry fields continue to debate the ‘facts’ of this diet. So, what is it and how is it supposed to work? Does it work?
There are compelling surface arguments on both sides, but you’ll need to scratch beneath to really get to the crux of what this diet is supposedly designed to achieve. If it does work, is it really because of the blood type you were born with and will live with for all your days? Or does it merely come down to healthier eating habits?
What is the blood type diet?
The idea of eating according to your blood type (O, A, B, or AB) all began with the publishing of the book ‘Eat Right for your Blood Type’ (a New York Times best-seller which has sold over 7 million copies and been translated into at least 52 languages) by naturopath physician, Dr Peter J. D’Adamo. The appeal of this diet, for the general public, is to trim down and achieve an overall healthier condition. These are the key selling points of this diet, as with most others that have gained popularity.
We all desire this, and so each diet that hits the market becomes an overnight sensation, making feature pieces in many publications. Depending who you talk to, you may get different viewpoints and a host of “it worked for me” but “not for me” result comparisons. Ultimately, just about every diet leaves you to answer the “does it really work?” question for yourself.
When it comes down to it, many of us don’t stick to a diet strategy for very long anyway. It’s ‘human nature’ to adopt a quick fix attitude with as little or the least complicated level of commitment as possible. By nature, when we have a goal, we have one purpose and tend to want to achieve that by venturing down one little path to make it happen. Once that is accomplished, the diet may take a back seat, and a yo-yo effect with weight may happen. There’s nothing healthy about that.
Anything to do with blood and blood type is not necessarily all that simple. The estimated volume of blood circulating our systems makes up approximately 7% of our total body weight. Blood has an influence on how everything in the human body functions. It’s essential for healthy tissues and organ function. When there is a break in this chain, health takes a knock and can sometimes result in serious medical conditions. So, how it is that a naturopath from Connecticut, USA developed a diet from such a complex portion of our bodies?
Dr D’Adamo’s hypothesis is based on the idea that the food we eat reacts chemically with whichever blood type we are. Thus, we should follow a lifelong diet and nutrition plan that is specifically designed for our individual blood types in order to better digest what we eat, lose weight (if desired) or maintain a healthy weight, have more energy and reduce our risk of specific disorders and diseases, we may be predisposed to because of our blood type. Sounds simple, right? It isn’t. There are many levels to this and it is incredibly fascinating to read the medical research that either supports or contradicts the reasoning.
Dr D’Adamo follows the thinking that there is a direct correlation between types of diseases and conditions we, individually, may be more susceptible to, and our specific blood type. Therefore, what we eat can help reduce the risk of developing a condition that debilitates our bodies, requiring medical treatment. In other words, the specific blood type you have already classifies you as more susceptible to certain illness or conditions, and what you eat is either going to serve your body well or aggravate this.
Dr D’Adamo thus believes that not every person should follow the same diet and nutrition plan because of the different blood types the human race has, as well as other differing factors and variables such as race, which influence outcomes. He believes that our tolerance levels for certain foodstuffs relate directly to our blood types and based on this, some need more of this and less of that (and vice versa), or to avoid certain food groups altogether. Dr D’Adamo has narrowed down 16 groups of food that are highly beneficial, neutral or should be removed from a diet altogether, making the plan a restrictive one for every blood group.
Dr D’Adamo has structured the blood types and their related food group diet plans as follows:
- Type O: The ‘ancient’ or oldest blood type (the hunter)
- Type A: The Agrarian blood type (the cultivator)
- Type B: The nomadic blood type
- Type AB: The modern blood type
Naturally, Dr D’Adamo’s thinking has sparked intense interest. Hence, the controversial debates that followed the release of his book (and continue today). We all wish to be healthy and try to make lifestyle choices to best accomplish this. Reading up on the basics of this diet may likely leave you nodding your head in agreement – it seems logical. There are, however, grey areas when you scratch the surface and this is where debate has led to substantial disagreement.
It’s an intriguing concept and for those involved in science and medical research, it’s too intriguing not to put to the test. The grey areas are where scientific / medical research has tried to separate the fact from the fad. Even logical thinking must be proven. There are many questions, as with any diet plan you commit yourself to.
For many it comes down to weighing out (pardon the pun) the pros and cons for yourself, as an individual. Do you feel good on this diet? Are you achieving your goal? The more pros there are, the more likely you are to jump up and down in agreement that the diet is fabulous and works! If not, human nature dictates that you’ll automatically dismiss it as rubbish because it failed you.
However you switch up your eating habits, it all comes down to how the diet makes you feel and whether you are generally healthier when following it. For science and those in the fields of medicine and nutrition, the questions and answers are not yet satisfied.
What is the thinking behind how this diet works?
Dr D’Adamo’s scientific basis for the blood type diet is broken down as follows:
- Molecular mimicry: A variety of microorganisms produce markers (antigens) in the body which are unique to one type of blood group or another. Depending on the blood grouping, these antigens are given different advantages unique to one of the different blood types. In just the same way, these markers can also be a source of trouble in their own right, according to a blood type grouping (i.e. working for or against your body according to your blood type grouping).
- Energy source: Bacteria appears to have a preference for certain blood type groupings and consumes blood type antigens as a source for energy. By-products of this may or may not be beneficial to the digestive tract of a particular person (depending on their blood type).
- Adhesion: Blood type antigens found in cells and in the mucus of the digestive lining, can be used by microorganisms, attaching themselves to tissues and cells throughout the body. In this way, it is believed that certain infections and conditions are directly linked with specific blood type groups (i.e. your blood type may make your more susceptible to certain conditions and ailments). Symptom ranges may vary, however from mild to severe.
- Inappropriate responses: Unexpected immune system responses may be triggered by certain microorganisms and directly relates to individual blood type groups (i.e. responses are different for each group). Infections (viral or bacterial) may affect different blood type groups in an excessive manner (i.e. leading to high levels of inflammation, and compromising the body’s response to combatting the infection) or generate additional shock or increased levels of stress.
Lectins and the blood type diet
When it comes to the blood type diet, much of the debate centres around lectins, which are protein compounds in foods that react with the molecules (binding themselves to sugar molecules) in the body.
Dr D’Adamo’s theory is that most human blood types evolved as the availability of different foods (i.e. food sources) changed over the course of history. Our ability to digest and metabolise lectins, in particular, changed through time and according to the blood types which developed.
The thinking ties in with the idea that our ancestral blood type is the fundamental factor that determines what we should be eating. The blood type O is labelled as ‘the hunter’ and is, according to Dr D’Adamo, classified as the oldest of the four main groups. ‘The hunter’ requires a diet that is rich in protein. Others disagree and feel strongly that Type A was actually the first blood group to evolve in prehistoric human history. Type A’s tolerate veggie diets better and are thought to have come about as a blood group with the development of agriculture, which in turn influenced eating habits.
Type B is classified as ‘the nomad’ and developed when society had a need for increased tolerance for a variety of different food types (when societies began consuming more dairy products). AB blood groups led to the need for combination dietary requirements (i.e. a combination of the requirements of both A and B blood types).
Dr D’Adamo makes the argument that the effect of lectins (chemical reaction) based on foods we eat and our individual blood type groups is inherently part of our genetic make-up. Our digestive and immune systems effectively maintain a ‘favouritism’ for foodstuffs that our blood group ancestors ate (due to their agglutinating properties).
These proteins act like super glue by attaching themselves to cells in the liver’s bile ducts and the mucus linings throughout the body. If you eat food containing lectins that are believed to be incompatible with your blood type (antigens), the protein then targets the bodily systems (organs like your liver, kidneys, stomach and gut).
Interactions with tissues can have a distressing effect on the body (i.e. leading to the development of a health concern or medical condition). Type A individuals could consume a bowl of butter beans (a legume also known as lima beans). The beans would normally digest through an acid hydrolysis process. Lectin proteins are resistant to this process in a type A group and as such, don’t effectively digest in the stomach, rather staying intact or with some nutrients being absorbed in the bloodstream. The intact protein then settles somewhere inside the body and becomes something like a magnet for the cells in that area. This causes clumping, which in turn has a negative effect for the area of the body this occurs in. This can lead to conditions such as irritable bowel syndrome (IBS) or cirrhosis of the liver, food allergies or perhaps problems with the kidneys if a blockage of blood flow occurs.
Other signs of a lectin problem in the digestive system can include things such as flatulence or bloating following a meal, bowel habit changes, hormonal fluctuations, skin breakouts, achy joints or muscles, or fatigue.
Dr D’Adamo explains that approximately 95% of the immune system in the human body protects us from lectin proteins, with much of these being absorbed from the food we consume. The remaining 5% filters through the bloodstream and have the aforementioned types of reactions, effectively destroying white and red blood cells.
Lectins, as part of the debate, are seemingly a complex issue, as the nature of these proteins varies widely. It all comes down to their source. Lectins found in wheat are different from those found in soy foodstuffs. Thus, they attach differently to various cells/areas in the body, and by extension will have different effects on the bodies of different blood types. According to the doctor, the effect of this is beneficial to one type group but destructive for another. Hence the need for completely different and structured diet plans. For instance, he suggests that lectins in soy are beneficial for the immune system of a blood type A person, guarding against cellular changes, which would otherwise be problematic in the body for those with other blood groups.
Some problem foods high in lectin, for each main blood type group, according to Dr D’Adamo are:
- Type O: Wheat, soy, Kidney beans and peanuts
- Type A: Tomatoes, eggplant (aubergine), lima beans and garbanzo beans (chickpeas)
- Type B: Soy, lentils, chicken and corn
- Type AB: Bell peppers, corn, chicken and Fava beans (broad beans)
To date, the diet disagreement centres around the notion that lectin reactions in the body are solely responsible for poor health and body disruptions, and are directly related to different blood type groups. Dr D’Adomo takes the stand that type O blood groups are wheat and dairy intolerant and thus have systems that cannot handle these foodstuffs very well, making them more prone to gluten intolerance or suffering wheat allergies.
Counteracting arguments take the stance that the effects are not solely due to blood type groupings alone. Lectins are considered antinutrients and the small percentage that has any agglutinating activity (i.e. elicit the clumping of red blood cells) affects all ABO blood types, not just one specific group. Thus, it is argued that the effects can’t be specific to one blood group and not another.
Negative effects are also specifically attached to the consumption of raw legumes, but is argued that this carries little weight as most are hardly ever eaten in this state, and are rather soaked and cooked before being consumed. Thus, any small percentage of lectins are destroyed anyway.
What should you be eating and doing to manage your lifestyle, according to Dr D’Adamo?
Dr D’Adamo maintains that each of us shares a common bond with our ancestors. This bond is fundamentally based on our blood type and the genetic information that has resulted in specific characteristics passed down through generations. It’s not just all about food habits.
Blood types are either secretors or non-secretors (this refers to the ability to secrete blood type antigens into tissues and fluids or not) and exist in every grouping (i.e. Type B’s can be both secretors and non-secretors etc.). A secretor places their blood type into their bodily tissues and fluids (such as saliva). A non-secretor places none or very little of their blood type into these areas of the body. Non-secretors lack the FUT2 secretor gene, which can be determined through blood analysis. Dr D’Adamo uses a unique software (genomic test kit to assess a person’s status) of his own as part of his offering for personalised plans.
The doctor defines the blood types as follows:
Type O – “The Hunter”
- The individual: Type O’s are the only blood group to carry two opposing antibody types (one against type A and the other against type B). Type O’s may be predisposed to illnesses and ailments such as thyroid disorders, stomach acid issues and ulcers. Type O’s are better able to digest foods that are both high in protein and fat than other groups. There are two chemicals used in the digestive tract (intestinal alkaline phosphatase and ApoB48, a lipoprotein) which are secreted in higher quantities. Thus, type O’s efficiently metabolise cholesterol in animal
products, as well as calcium. The downside is that carbohydrates are more easily converted to fats and triglycerides (these are stored in fat cells) and high levels of these in the blood are often an indicator of increased risk for heart disease and stroke. Lectins in grains can also react negatively in type O’s by causing auto-immunity or inflammation in the body. Type O’s are ‘fight or flight” people when it comes to stress reactions. Excessive anger, hyperactivity, and temper tantrums are enough to cause a chemical imbalance in the body, making type O’s susceptible to destructive behaviours, especially when depressed, bored or incredibly tired. That said the release of dopamine and associated feelings of reward are also on the agenda, making them vulnerable to certain behaviours relating to risk-taking, sensation-seeking, substance abuse or impulsivity. Type O’s are said to be prone to asthma, hay fever, and other allergies, as well as arthritis.
- The diet should include: Lean, organic meats, fish, poultry, as well as fresh fruits and vegetables.
- The diet should restrict or avoid: Wheat, dairy, grains, potatoes, legumes, caffeine and alcohol.
- Lifestyle habits: Type O’s can benefit from brisk, regular (3 to 4 times a week) exercise that targets the cardiovascular and muscular skeletal systems. This in turn has a beneficial chemical response to emotional well-being. Aerobic activity for at least 30 to 45 minutes a session is the best way to energise a type O body.
Type A – “The Agrarian or Cultivator”
- The individual: Type A’s emerged as a result for the struggle to survive when hunting game stock began to become scarce. Great game herds in Africa, for instance, began to dwindle rapidly and humans were forced out of their ancestral homes into Europe and Asia. This led to the establishments of communities which were stabilised with the cultivation of livestock and grains (effectively phasing out the hand-to-mouth ‘hunting’ lifestyle). Type A’s eventually became able to utilise nutrients from carbohydrate sources, which to this day affects this group’s digestive structure. Type A’s have low levels of hydrochloric acid in the stomach, but high levels of intestinal disaccharide digestive enzymes. This enables efficient digestion of carbohydrates, but also makes a type A body less able to metabolise fats and animal proteins as effectively. Type A’s also, due to the nature of developed communities over the ages, favour structured, harmonious and rhythmic lifestyles, surrounded by positive and supportive individuals. Type A’s can develop an increased sense of isolation with the harried pace of society and thus internalise stress. Balance is key for type A’s and these individuals tend to prefer a proactive mix of lifestyle strategies, gentle exercise, mental clarity and hormonal equalisers. Internalised stress (which results in naturally high levels of cortisol, a stress hormone) can negatively impact a type A’s health and can lead to conditions such as diabetes, cancer, and cardiovascular
disease or other problems such as disrupted sleep patterns, daytime brain fog or mental exhaustion, muscle loss and fat gain. Insulin resistance, obsessive-compulsive disorder and hyperthyroidism are also negative effects for type A’s. This blood group is often described as analytical, a good listener, creative, detail-orientated, inventive and sensitive to the needs of others.
- The diet should include: Soy proteins, grains and vegetables should be eaten in as natural a state as possible (organic and fresh). Type A’s best benefit from a vegetarian diet. Type A’s can consume protein, but it is best eaten at the start of a day (and in lesser amounts at the end).
- The diet should restrict or avoid: Sugar, caffeine and alcohol. Type A’s should also be mindful of skipping meals and rather eat smaller or more frequent meals to stabilise blood sugar levels.
- Lifestyle habits: Type A’s fare better by limiting exposure to loud noise, crowds of people, violent movies and television programmes and extreme weather conditions (very hot or cold). Smoking, strong smells, excess sugar and starch, lack of sleep and overworking can also negatively impact the system of a type A and intensify susceptibility to stress. Elevated cortisol make it more difficult for type A’s to overcome stress. Calming exercise works best for this blood group – yoga, Tai Chi, deep breathing and medication (30 to 45 minutes a session, at least 3 times a week). Intense, physical activity is not necessarily advised against for type A’s, but merely needs to be balanced. Overtraining or too much (intense) aerobic activity can elevate cortisol levels.
Type B – “The Nomad”
- The individual: The doctor ties this type with ‘balance’ and believes that the blood group developed in the area of the Himalayan highlands (now Pakistan and India). Populations were from the hot and lush savannahs of eastern Africa and migrated to the cold Himalayan mountains. The body thus needed to adapt as a result of climatic changes. The blood type emerged in the great tribes of steppe dwellers (Caucasian and Mongolian) who dominated Eurasian plains and eventually the Indian subcontinent as well. Tribes developed a strong lifestyle of herding and domesticating animals. Diets became heavily based on meat and cultured dairy products. Migration patterns have resulted in high type B population numbers in Japan, China, Mongolia, India and North Korea. Type B’s are thus able to thrive in changeable conditions but are highly sensitive to the effects of slipping out of balance. Like type A’s, B groups are also prone to higher than normal levels of cortisol when under stress which can make them more susceptible to inflammation and Syndrome X (slow growing / lingering viruses such as multiple sclerosis and lupus), diabetes and other autoimmune diseases. Type B’s are also easy-going, natural-born networkers, idealistic, subjective, intuitive, insightful, creative, flexible and original by nature. Type B’s are said to learn best through listening, taking time for reflection and interpreting their observations for themselves. Type B’s have a high allergy threshold and only typically develop allergic reactions by eating incorrect foods.
- The diet should include: Lamb or mutton, goat, rabbit, venison, eggs, green vegetables and low-fat dairy.
- The diet should restrict or avoid: Corn, wheat, lentils, buckwheat, peanuts, sesame seeds and tomatoes. These foods affect the metabolic process and contribute to weight gain in type B’s, causing problems with fatigue, hypoglycaemia and fluid retention. Chicken should also be avoided due to agglutinating lectins that attack the bloodstream, which can then lead to the development of immune disorders or stroke.
- Lifestyle habits: High levels of cortisol can contribute to depression, hyperthyroidism and insulin resistance. Type B’s are supposedly able to gain physiological relief from stress and achieve emotional balance through meditation and visualisation techniques. Thus, physical exercise that challenges the mind as well as the body is best for type B’s. Tennis, martial arts, golf, hiking and cycling are best suited to type B’s. This group can fare well by keeping their mental capacity sharp too by doing tasks that require concentration, such as crossword puzzles or learning a new language.
Type AB – “The Enigma”:
- The individual: Type AB’s are rare (less than 5% of the world’s populations) and came about due to intermingling (rather than evolution which applies to all other groups) between types A and B (A and B gene variations or alleles happily co-exist with one another in this group). Type AB’s share benefits and challenges of the two blood groups (A and B), displaying characteristics that lean towards being more A-like at times, and B-like at others, or even a fusion of both. This group is prone to low stomach acid (like type A’s), but also shows an adaptation to meats (like type B’s). Thus, type AB’s lack enough stomach acid to metabolise meat, which is then stored as fat. This can result in problems such as stomach cancer. This group has fewer issues with allergies, but are more prone to anaemia, cancer and heart disease. Type AB’s are thought to be spiritual, intuitive, passionate (especially when it comes to belief structures), emotional, friendly, empathetic and trusting. Did you know, Marilyn Monroe and John F. Kennedy were type AB’s?
- The diet should include: Seafood (such as salmon, sardines, red snapper, tuna and mahi-mahi), tofu, green vegetables, beans, grains and dairy (especially yoghurt).
- The diet should restrict or avoid: Caffeine, alcohol, smoked or cured meats. Dr D’Adamo also advises type AB’s to avoid combining starch and protein in one meal as this affects digestive secretions, resulting in food staying in the stomach for longer.
- Lifestyle habits: Type AB’s most resemble type O’s when it comes to the effects of stress, but can also suffer physical consequences of high emotions (like type B’s). Internalising emotions is damaging to overall health and is best balanced out with calming activities and intense physical exercise (such as 3 days of aerobic activity, like biking or running for 45 to 60 minutes a session, and 2 days of yoga, stretching or Tai Chi).
Is there any scientific basis to this?
"There had to be a reason why there were so many paradoxes in dietary studies and disease survival, why some people lose weight and others do not on the same diet or why some people keep their vitality as they age, and others do not," says Dr D'Adamo. “Blood type is the key that unlocks the door to the mysteries of health, disease, longevity, physical vitality, and emotional strength."
The doctor stipulates the following with regards to blood type and overall health:
- Medical conditions and diseases: For instance - Type O’s are at a low risk for heart disease, but at higher risk of stomach ulcers. Type A’s have a higher risk of microbial infections. Type B’s and AB’s are at higher risk of pancreatic cancer.
- Reactions to stress and stress hormones: For instance - Type O’s have a distinct ‘fight or flight’ response, resulting in an overproduction of adrenalin which takes some time to clear from the body. Type A’s produce higher levels of cortisol.
- Gut bacteria and nutritional needs: Different blood groups have different gut bacteria, as a result of evolutionary changes to eating habits. Dr D’Adamo recommends a low-lectin, non- agglutinating diet plan that “creates a hospitable environment for your ‘good’ intestinal flora” and thus reduces disease risk.
The opposing argument
One of the key attractions associated with this diet is weight loss. Like most diets, losing excess weight is the nucleus around which the entire plan is predominantly based. Improved health and reduced health complication risks follow suit as added attractive benefits.
The blood type diet is no different in this regard. The bottom line for most who have researched and offered up an opinion about this diet, irrespective of specialist area of expertise, is that any plan that promotes the avoidance of processed foods (and some carbohydrates) is good for you, no matter your blood type.
Can you lose weight? Weight loss and overall healthiness is bound to follow when reducing the intake of processed foods (and the associated calories) and is sure to help anyone achieve a better physical state. Thus, the consensus with opposing viewpoints is that overall healthy eating benefits everyone and is not blood type specific.
Depending on the type of foodstuffs incorporated in the individual diet plans, weight loss is achieved on different levels. Viewpoints therefore agree, that weight loss on this diet is achievable, but not because it specifically works as a result of blood group adaptations or influences, but rather because the diet is restrictive of certain foods.
When it comes to lowering risk of specific medical conditions, disagreement continues. Does this diet really improve your digestion ability (based on blood type) and give you more energy? A diet plan developed by Dr D’Adamo can and does seemingly contradict others that a medical doctor will develop for a patient with, for example, diabetes. One will encourage a high protein diet. Another will request that you limit or avoid dairy. A doctor may not advise a person with a chronic condition to cut out a specific food group altogether. The blood type diet is more restrictive in this sense.
Conditions such as heart disease, hypertension (high blood pressure), and cholesterol have critics up in arms too. Low-fat and low-sodium diets are essential for these conditions. Few feel Dr D’Adamo has adequately addressed this in his diet plans.
Exercise and the required amounts (whether it be of the aerobic variety or calming practices) is also still a debatable area. How much is really good for you per week?
So, yes, you may very well lose weight, feel healthier, have more energy and have improved digestion on the blood type diet. But no, there is seemingly not enough scientific evidence that substantially agrees that the diet effectively reduces risk for disease susceptibility or that this happens in any way, shape or form as a direct result of your blood type. The fact that it may work merely comes down to your own individual ability to stick to a set way of eating and exercising as part of your lifestyle.
Other downsides (for some people) are that the raw, organic and lean nature of the diet will effectively mean your choices of foods are limited, will require time in the kitchen to prepare and will be a little taxing on your purse. For the time-poor city slicker, this may not be attractive. Organic foods are also not known to be incredibly affordable, the world over. Expenses can thus add up if you choose to buy into the doctor’s range of supplements too.
So, who’s argument is most true?
The jury may still be out on this one. There’s no doubt about this, this diet and its hypothesis is intriguing. There may still be, decades after the initial publication, professionals researching and conducting comprehensive tests to either prove or disprove the notion of a direct linked to blood type groups. With so many influencing components and the complex nature of the body and its functions, this topic may be a hot debate for a while yet.
Both sides seemingly pose logical arguments. The disproving side advocates (loudly) that there is no scientific evidence. Dr D’Adamo interjects as often as possible to provide his carefully researched side of the story, which supports his hypothesis wholeheartedly. He may even agree that studies conducted thus far have been poorly designed. Blood types are a complex thing when looking at such a wide range of variables affecting the human body. This makes any research highly sensitive and incredibly complex.
It’s a constant tennis match. For many, restrictive diets with a specific purpose (like losing weight) are attractive (and often used in a short-term capacity). For others, a well-balanced and healthy diet, limiting intake of certain foods without cutting them out completely is the way to go. The bottom line, is it comes down to YOU and what you put into your body for healthy living to meet necessary nutritional requirements. We all fare differently when it comes to certain foodstuffs. Some may support Dr D’Adamo in his thinking as the fundamental reason for this. Others not. Any diet appropriate for your individual metabolism is likely to show positive effects on your overall health.
If you’re curious to try this diet, go for it. Remember that eating is never a case of ‘one size fits all.’ You may have to customise, modify and adapt any diet plan you take on to make it your own for maximum comfort and sustained commitment.
If you have a medical condition, especially a chronic illness, or even just known food intolerances or allergies, seek advice from your primary medical professional (general practitioner) before you adapt your eating habits. The blood type diet has pros and cons, and restrictions may very well impact the nature of a medical condition. It is best to not take a chance if you have a known condition which can be aggravated by food.
For the most part foods included in the diet are healthy. The general consensus is that, for the most part, it will have a healthier effect, no matter your blood type. The debate is the relevance of blood type as the dictator of the diet, and if there is an existing medical condition, whether or not a restrictive plan will negatively affect an illness.
If it works for you and you feel you can stick to it without any disruptions to your overall health, it’s not the worst way to eat. But if it (your current diet) ain’t broke, there’s no need to fix it either. Happy eating!