Blood Type O Diet Plan

"Eat Right for Your Type" is an eating plan devised by Dr. Peter D'Adamo that is based around a chemical reaction that occurs when you consume specific types of foods that contain lectins, which are a type of protein. Lectins do not easily break down and have agglutinating properties, which means they may bind to the wall of the gut and possibly damage the lining. The diet teaches that lectins affect various blood types differently and advises which foods to eat to prevent lectin damage, depending on your blood group.

Meats

People with the O-blood type are referred to by D'Adamo as "hunters" who tolerate a high-protein carnivorous diet well. As a type O, you digest meat efficiently due to your hardy digestive tract and high stomach-acid levels. General food recommendations for type Os include poultry, red meat, fish and also vegetables, fruits, legumes and limited grains. When on a weight loss diet, types Os can consume most types of red meat and liver. Meats to be avoided are bacon, ham, goose or pork.

Seafood

Type Os react very well to fish and seafood. Many kinds of seafood contain high levels of iodine, which help thyroid function. Fresh herring, cod and mackerel are optimal choices, while barracuda, pickled herring, catfish, caviar and smoked salmon should be avoided.

Dairy

Type Os should restrict consumption of dairy products and eggs, as their system does not metabolize these foods well. This can lead to stomach discomfort and weight gain. Goat cheeses or soy milk products can be eaten in moderation, but all other dairy foods are not recommended for O types.

Fruits and Vegetables

Avocados should always be avoided by type Os. When on a diet, optimal vegetable choices are lettuce, kale, spinach and broccoli. Corn is very detrimental for weight loss in type Os due to its effect on insulin production. Cabbage, brussels sprouts, cauliflower and mustard greens should also be avoided, as they inhibit thyroid function in O types.

The best fruits to eat are dark-colored fruits such as plums, figs and prunes if you are a type O. Dr. A'damo claims melons may trigger allergies, and oranges, tangerines, blackberries, strawberries and rhubarb could cause stomach irritations in type Os, as they have a high acid content.

Legumes

Generally speaking, if you are a type O, you won't utilize beans well, and they may lower the acidity of your muscle tissue, thus preventing the metabolism of some nutrients. When on a weight loss diet, avoid beans; when you reach your ideal weight, aduke, azuki or pinto beans and black-eyed peas can be eaten in moderation.

Grains

Type Os do not tolerate whole-wheat products. Initial weight loss for type Os is promoted by restricting consumption of grains as well as that of breads and beans. One of the leading causes of weight gain in type Os is gluten, which is found in wheat germ and products made with whole wheat. This can slow down the type O metabolic rate by interfering with insulin efficiency. Therefore, Dr. D'Adamo recommends avoiding grain products completely if you are a type O who needs to lose weight.

Expert Insight

Mayo Clinic nutritionist Katherine Zeratsky, R.D., L.D., claims there is no scientific evidence to back up the blood type diet's effectiveness. Zeratsky suggests that eating healthy foods and exercising regularly is more likely to be beneficial for your weight loss efforts and health than eating foods based on your blood type.