Most health experts would agree with D?Adamo that a ?one size fits all? approach to dieting is wrongbut few would say that a plan based on blood type is the answer. In fact, there?s no science to support the strategy. Chances are meat-loving Type AB dieters will see through the hocus-pocus pretty quickly since, according to the regimen, they should dine on tofu rather than steak. For others, the unique approach might sound promising at first, but chances are it?ll end up being a big headache.
Basic principles:
There are four blood types: A, AB, B, and O. People with different types require different foods for optimal health. The diet isn?t really about dropping pounds, but D?Adamo claims that ?weight loss is one of the natural side effects.? Dieters need to avoid foods that are toxic to, or promote weight gain for, their particular type. Recommendations for exercise also vary depending on blood type.
How the diet works:
Sixteen food groups (such as meats, dairy and eggs, grains, and spices) are divided into three categories: highly beneficial foods, neutral foods, and foods to avoid. The idea is to eat moderate portions from the beneficial and neutral lists and steer clear of items on the taboo list. For instance, Type O?s should avoid ice cream, caviar, and (no kidding) barracuda. Type A?s must abstain from buttermilk, sherbet, and pistachios. Taboo for Type B?s are ketchup, corn syrup, and rhubarb. The no-no?s for Type AB?s: nearly every meat on the planet, including chicken, pork, veal, ground beef, and buffalo.
What you can eat:
Again, everything hinges on your blood typeno calorie counting, no measuring portions. Type O dieters fare well with high-protein meals that include lean organic meats (no more than 6 ounces per meal) and limited amounts of grains, legumes, and beans. Dairy, on the other hand, is poorly tolerated, and wheat products typically cause weight gain. Type A?s do best on a high-carb, low-fat vegetarian regimen. Type B?s can enjoy a varied diet, including dairy and grains. Get the picture?
Does the diet take and keep weight off?
No clinical data. D?Adamo offers anecdotal evidence that the diet ?works for 9 out of 10 people.? But it?s unclear if by ?works? he means a drop in pounds or an improvement in overall health.
Is the diet healthy?
Debatable. There?s no concrete meal plan here to evaluate. Dieters will be choosing and avoiding foods based on lists. They could choose wisely, but they could just as easily choose poorly.
What do the experts say?
?We all have individual needs, but basing what you eat on blood type is ridiculous,? says registered dietitian Jane Kirby, author of Dieting for Dummies (Wiley, second edition, 2003). Edee Hogan, RD, a nutrition and culinary consultant in Washington, D.C., agrees: ?There?s no indication that blood type has anything to do with anything other than blood type. Your basic nutrition needs are the same whether you?re A-positive or B-negative.?
Who should consider the diet?
Nobody.
Bottom Line:
Don't bother.


