How to Help an O Blood Type Lose Weight

The food choices to help someone with type O blood lose weight is described in the book, "Eat Right For Your Type," by Dr. Peter D'Adamo, a naturopath. D'Adamo continued the work of his father, naturopathic doctor James D'Adamo, who noticed some diets worked better than others with his patients. Peter studied the agglutination process occurring between certain foods and specific blood types and believes it is caused by the way the blood types evolved. He proposes that the earliest human blood type was type O.

Losing Weight with Type O Blood

Step 1
Look up your blood type to make sure you are O, or if you have never had your blood typed, go to your local hospital or clinic for a blood test. Whether you are positive or negative does not matter. Type O's ancestors were hunter-gatherers, who thrived on intense physical exercise and animal protein. Peter says the success of the type O diet is dependent on using lean, chemical-free meats, poultry and fish.

Step 2
Eat lean beef, lamb, turkey, chicken and oily cold-water fish such as herring, cod and mackerel. Rainbow trout, salmon, swordfish and sole are also good choices. Seafood contains iodine, which assists type Os with thyroid function. The more stressful your job or vigorous your exercise program, the higher grade of protein you should eat. Note that your ancestors did not consume 16-ounce steaks, due to the scarcity of meat. Aim for no more than 6 ounces per meal.

Step 3
Consume monosaturated oils such as flaxseed and olive oil for their positive effect on the heart and arteries. Pumpkin seeds and walnuts are good sources of supplemental protein. Leafy green vegetables containing vitamin K, such as kale, collard greens, romaine lettuce, broccoli and spinach, are good for type Os because they help with blood clotting. The most beneficial fruits are figs, plums and prunes, due to their alkaline rather than acidic reaction in your digestive tract.

Step 4
Limit the consumption of dairy and eggs to three to four times weekly, unless you are of African ancestry; if so, limit them altogether. Soy milks and cheeses are good high-protein alternatives to dairy products that are not properly metabolized. Although type Os don't process beans very well because they interfere with the metabolism of other nutrients, they can eat aduke, pinto and black-eyed peas.

Step 5
Avoid the following foods that encourage weight gain: wheat and corn, which interfere with insulin efficiency and slow metabolic rate; kidney and navy beans, which impair the utilization of calories; lentils, which do not allow nutrients to be metabolized properly; and cabbage, brussels sprouts, cauliflower and mustard greens, which inhibit thyroid production.

Step 6
Exercise vigorously with intense physical exercise to keep weight under control and release stress. The systems of type Os are suited for heavy exercise. The following exercises are recommended at least three to four times a week: aerobics, swimming, jogging, weight training, treadmill, stair climbing, martial arts, contact sports, calisthenics, cycling, brisk walking and dancing or roller skating. To derive maximum cardiovascular benefits from aerobic exercise, elevate your heart rate to 70 percent of your maximum heart rate for at least 30 minutes.


The Mayo Clinic reports there is no scientific evidence that the blood type diet is any more effective than other diets for weight loss. Despite a number of positive testimonials by individuals who have successfully used the diet, the Mayo Clinic notes there is no solid research to support its claims.


Follow the diet exactly as it appears in "Eat Right Four Your Type" by Dr. Peter J. D'Adamo, adding in foods that encourage weight loss and leaving out those which interfere with it. By doing this, you can determine precisely if the diet works for you.

Things You'll Need

A copy of the blood type diet for type O
Foods required on the diet