Diet 101: Blood Type Diets
Is the secret to weight loss determined by your blood type? If you ask some blood-type diet fans, yes. If you ask us, doubtful. Never heard of this diet craze? Here are the basics.
Diets based on blood type suggest that your type (that is, A, B, AB or O) determines your dietary needs and dictates how your body digests food and burns calories. Advocates associate food selections around ancestry and evolution. For example, ancient man supposedly had type O blood and so folks with this blood type are better off eating animal proteins (since meat was a staple in the diet way back when). Grains and dairy (i.e. more cultivated food) were less common, and therefore type O'ers don't digest them well. These diets also propose that your blood might mean you're more prone to particular food allergies, aversions, eating habits and even medical conditions. They often offer advice on what types of physical activity are best for your type types.
The book Eat Right For Your Type, by naturopath Dr. Peter D’Adamo, breaks down the specifics. The main focus of the diet is to eat whole foods (no processed junk allowed), but there are laundry lists of foods that allowed and forbidden. There’s also a painfully long list of the vitamin, mineral and herbal supplement he thinks you need. Here are some of the what-to-eat highlights:
Type O: Lots of animal protein but only small amounts of grains and dairy
Type A: Lots of grains, fruits and vegetables but very limited amounts of meat and dairy
With this diet, you can forget about enjoying many (or most) of the foods you're used to eating -- especially the junky stuff. By drastically alter your eating habits, there’s a good chance you’ll eat less calories and therefore lose some weight, but this has nothing to do with your blood type. Taking in too few calories is not only bad for your metabolism, but it usually ensures that you will gain the weight back when you revert to your old ways. Cutting out large groups of food puts you at greater risk for serious nutrient deficiencies, and taking on a complicated supplement regimen can be extremely dangerous -- especially if you're on prescription medication.
Bottom Line: A blood-type diet may focus on healthy foods, but overall it is way too complicated and restrictive to be realistic or good for you.