Diet Myths Busted
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Is there any truth to the idea that individual blood type should dictate what we eat? How can I tell if a diet is based on science or is just a gimmicky fad?

The blood type diet is a diet advocated by Peter D'Adamo, a naturopathic physician, and outlined in his book Eat Right 4 Your Type. D’Adamo claims 90% of what you need is related to your basic blood type which could be A, B, AB or O.

1.      Blood group O is believed by D'Adamo to be the hunter. The diet recommends that this blood group eat a higher protein diet. D'Adamo bases this on the belief that O was the first blood type, originating 30,000 years ago.

2.      Blood group A is called the cultivator by D'Adamo, who believes it is a more recently evolved blood type, dating back from the dawn of agriculture, 20,000 years ago. The diet recommends that individuals of blood group A eat a diet emphasizing vegetables and free of red meat, a more vegitarian food intake.

3.      Blood group B is, according to D'Adamo, the nomad, associated with a strong immune system and a flexible digestive system. D'Adamo claims people of blood type B are the only ones who can thrive on dairy products. D'Adamo believes blood type B arrived 10,000 years ago.

4.      Blood group AB, according to D'Adamo, the enigma, the most recently evolved type, arriving less than 1,000 years ago. D'Adamo thinks this blood type should adopt a diet that is between blood types A and B.

We have almost 7 billion people on our planet and according to D’Adamo, 4 basic diets can accommodate ALL of these people. That alone is a big red flag. It is not reasonable to think all people can only eat one certain way. This does not take into account culture, economics, or foods cultivated in different parts of the world. It also doens't take into account that people with eating disorders don't have their blood types fall into these catagories once an eating disorder is discovered.

Here’s another red flag: I have type O and my husband is type A. We both like and eat a similar diet without any problem. However according to the blood type diet, I should eat lots of protein and my husband should be a vegetarian. There is no real scientific evidence that supports the concept that blood type is a major factor in what you should eat. When we give food to people in other countries, we never ask what blood type they have; we ask what food they need. 

Basic logic is one of the best ways to separate gimmick from fact. When you were little did your doctor, mother, grandmother, teacher or anyone ever ask you what your blood type was in relation to food?

Our obesity crisis didn’t really take off until the low/no fat diet was introduced along with the wide availability of prepackaged processed food.


I was told that after working out, if I don’t eat within 45 minutes my exercise was wasted. Is this true? Sometimes I can’t get anything until one or two hours after working out. Does this mean I shouldn’t work out unless I can get something to eat?

The first hour after a workout is considered the body's "golden hour." During this time depleted glycogen stores are replaced and the enzymes that convert glucose into glycogen are in a state that sugar can be consumed and is rushed directly to the muscles. A post-workout meal or drink is also important in replacing fluids lost through sweating to rehydrate the body. This is important especially if you are training very hard daily, such as a runner preparing for a marathon, or if you are an Olympic athlete or body builder. In these cases, restoring the glycogen levels in muscles is important since they will go under heavy fire again soon.  However for the average gym rat, the glycogen will be rejuvenated within 24 hours.  If you work out regularly, you have a storage of glycogen built up.  If you didn’t, you would have a very hard time coming up with the energy for working out the next day.

No work out is ever wasted.  If you can eat within that golden hour, so much the better; it will help with recovery. However if you can’t eat for an hour or more, you still benefit from your workout. If you are really concerned about it, carry a piece of fruit with you or a hard boiled egg. I often teach a Spinning class in the morning and then have lunch with my husband.  It is typically an hour to an hour and a half before we can get to lunch. I can always stop and have a quick small snack or even bring something to snack on. Either way, I get a great benefit from the workout!