The Blood Type Diet – Real or Not?
I don't mind fad diets. They provide a great pastime for hundreds of millions of people (many of them not as overweight as they think), they make writers rich, and everyone is happy, but I do have an instinctive dislike of bad unsupported science.
The weapon of bad science is often anecdotes. Usually the anecdotes have good hair and good teeth, and they look straight at the camera and say "The [insert fad diet name] changed my life and in only six weeks I saw tremendous results. I've been yo-yo dieting for years, and then a friend suggested [fad diet]." The director shouts "cut! That's a wrap" and the actress gets paid for her time. You think to yourself - well, that sounds great, I should try it out, and go buy the book/powder/abdominator etc, along with a million others, while at the same time making the promoter a few more millions of hard cash.
Semi-scientific claims are also a problem. You hear something that sounds like evidence, but actually isn't evidence enough. Dieters often feel better in the first weeks of a diet, simply due to the Placebo Effect and because they feel more in control of their lives. They also tend to control their calorie intake a little bit better when they mind what they eat, so their weight does drop. A few weeks down the line though, when they fail, they often blame themselves, not the fad diet. In their minds the diet is good, but they are "bad".
This diet's inventor, Dr. Peter D'Adamo, says that the Blood Type Diet (and his book Eating Right 4 Your Type) is based on analysis of hundreds of scientific article studies, and on further analysis of the cases of respondents from the author's website registry. That's all very well but really isn't sufficient evidence. I prove that my own theory is true, is usually a recipe for shaky science, especially if you have a best-selling book at stake.
As the author of the Blood Type Diet knows very well, if there is any truth in his claims, he shouldn't look for support for his own diet in his own research and in his own patients - A respected academic needs to commission unbiased double blind scientific experiments to prove or disprove his theory. Until then, no doubt, people will continue to follow his diet - so I can see why scientific assessment would not be an attractive prospect for a prosperous theory.
The Blood Type Diet - further reading:
- The website of the Diet's author, Dr. Peter D'Adamo (for balance).
- The 'Blood Type Diet:' Fact or Fiction? by Dr. Michael J. Klaper MD, Director of the Institute of Nutrition Education and Research.
- Blood Type Diet Review By Dr. M. Diennet M.D.
- Registered dietician, Andrea Giancoli:
VideoJug: Blood Type Diet Analysis
This article is included in the Weight and Fitness Forum Blog Carnival