Blood grouping is a system that identifies different blood types by identification of molecules found on the surface of red blood cells. The nature of the molecules (also known as antigens) is determined genetically and hence may vary from individual to individual. The commonest system used is the ABO system which groups blood into A, B, O or AB and the Rhesus (Rh) system which can be positive or negative. Combining the two systems, one can have A+ or A-, O+ or O- etc. Other existing systems include Duffy, Lewi, Kell, Kidd etc but are not commonly used clinically

Apart from determining the type of blood to be transfused to a recipient, these blood groups also determine the type of diet which is appropriate for an individual. Some diets are not recommended for particular blood groups because this can lead to excessive weight gain, food allergies, heart burn or diabetes thus certain foods are recommended and others discouraged as follows:

Type O blood group (Meat eaters): They should eat a high-protein diet heavy on lean meat, poultry, fish, and vegetables, and light on grains, beans, and dairy. Avoid Wheat, corn, kidney beans, navy beans, lentils, cabbage, Brussels sprouts, cauliflower and mustard greens

Type A blood group (Vegetarians): A meat-free diet based on fruits and vegetables, beans and legumes, and whole grains ideally, organic and fresh. Avoid Meat, dairy, kidney beans, lima beans and wheat

Type B blood group (Balanced omnivore): There are encouraged to eat Meat (no chicken), dairy, grains, beans, legumes, vegetables. Avoid corn, wheat, buckwheat, lentils, tomatoes, peanuts, and sesame seeds.

Type AB blood: Should have mixed diets in moderation. Foods to focus on include tofu, seafood, dairy, and green vegetables. People with type AB blood tend to have low stomach acid. Avoid caffeine, alcohol, corn, seeds and smoked or cured meats.

However, this kind of diet restriction due to blood group does not put into account people’s dietary preferences. One may eat foods not recommended for his/her blood group but if it causes discomfort or medical issues, then in should be eaten in moderation or avoided completely. Not at all times will discouraged foods cause trouble to the eater. Take note that following this diet plan may also deny one a balanced diet. Generally, one can eat whatever he/she feels like so long as it’s healthy and doesn’t cause discomfort regardless of his/her blood group type.