The efficacy of the blood group diet, a popular diet which is frequently mentioned in the media and is preferred by some people trying to lose weight, is still disputable. This diet was first advocated by Peter D'Adamo, a naturopathic physician, and his theory is that the ABO blood type is the most important factor in determining a healthy diet. D'Adamo's idea is that human blood type is key to the body's ability to differentiate “self from non-self.” He states that substances called “lectins” in food react differently with each ABO blood type, and to a lesser extent, with an individual's secretor status. Dr. Nabeela Azb, a dietitian at The Saudi Chinese Center founded by Dr. Riyadh Al-Hajn, said that the center doesn't agree with the principles of the blood group diet, since it is still arguable and still a theory not a scientific fact. “Dr. Hamad Al-Mane'e, the Minister of Health has asked doctors not to use the blood group diet and ordered the closure of one laboratory which had started applying blood group diet procedures,” said Dr. Azb. Through his books, such as “Eat Right 4 Your Type”, D'Adamo quotes the works of biochemists and glycobiologists who have researched blood groups, claiming or implying that their research supports this theory. On the other hand, Dr. Azb refutes this theory saying that one's blood type doesn't relate to one's weight in any way, since all food types are turned into simpler substances depending on the type of food consumed, which affects the body mass. “For example, if we say that people with blood type o should avoid eating foods that contain calcium, they will suffer from osteoporosis,” said Dr. Azb. Dr. Azb said that some people might have hereditary tendencies for certain diseases and disorders, which has nothing to do with one's blood type, and which cannot be treated by merely eating or avoiding certain foods. “As a dietitian, I prefer the calorie-dependant diet which is based on reducing the intake of extra calories by eating a balanced meal,” said Dr. Azb. Talking about other diet fads, Dr. Azb said that the “protein-dependant” diet has a very bad effect on health, since it overloads the liver and kidneys with proteins and increases ketone bodies in the blood. “The protein-dependant diet deprives one's body of carbohydrates and fats, which are the normal energy-giving food sources, forcing the body to produce energy from protein,” said Dr. Azb. People who follow the protein diet may have a lot of side effects like nervousness, headaches and vision problems because the high levels of ketone bodies affect the nervous system. “Similarly, the Atkins diet which advises people to depend only on protein and fat and completely cut out carbohydrates from their food can be dangerous for many people,” said Dr. Azb. For people who want to lose weight and keep it off, Dr. Azb recommends consulting a qualified dietitian and not following the latest fad in diets, without considering their serious health consequences.
