This diet started as another weigh-loss book. “Eat Right for your Type” was written by Peter J. D’Adamo, ND, a naturopathic physician, and published in 1996.
The theory behind the diet is that different lectins, proteins found in all foods, are not compatible with all types of blood and can either harm you or benefit you depending on your blood type. Type A’s, for example, should only be vegetarians, while type O’s should eat mostly meat and avoid carbohydrates.
There is no calorie counting and no restrictions on fat intake.
The diet can be very restrictive. Type O’s, for instance, are told to avoid all carbohydrates, most dairy products, avocados and other vegetable fats, and certain fruits such as oranges. D’Adamo goes as far as claiming that certain diseases, such as diabetes and cancer, are closely related to blood type, and can be avoided by strictly following his diet plan.
THE GOOD: Some recommendations, such as cutting down on processed foods, are sound, although they are also common sense. Weigh loss is likely to occur because of the reduced intake of calories.
THE BAD: There is no scientific data whatsoever to support these claims. “I’ve never heard of any issues related to blood type and diet and immunogenicity or organ toxicity,” says O’Donnell. The diet excludes whole classes of food and can result in vitamin and mineral deficiencies.
THE VERDICT: Another fad diet with no real science support behind.
Always be sensible about dieting and exercise. If you suspect you have a health problem, if you are severely overweight, or if you are pregnant or lactating, consult your doctor before starting any diet program.