Book review: Blood Type Diet

I reviewed the diet book Eat Right for Your Type by US naturopathic physician Peter D'Adamo in 2009. It was part of the premium, paid content of the Foodwatch site at the time. Since then, the book has become a bestseller with its promise of helping you avoid infections, lose weight, fight life-threatening diseases and slow ageing. So I've decided to make my review available to all Foodwatch readers. 

How does it work?

Dr D'Adamo believes that your blood group - O, A, B or AB - determines the type of foods you should eat. He classifies people according to their blood type and then prescribes a diet which he says is in accordance with what people with that blood type need. 

For example, if you are blood type O (the most common type), then you are classified as ‘The Hunter'.

According to Dr D'Adamo, you should consume a high-protein hunter-gatherer diet based around meat, poultry and fish and you must restrict grains, breads, dairy foods and pulses.

Blood group A is classified as ‘The Agrarian' and is the opposite of Type O. It should ‘flourish on a vegetarian diet, the inheritance of farming ancestors.'

According to nutrition researchers, there's no relationship between blood groups and metabolism. One researcher has been quoted as saying there's ‘no more evidence linking blood type to food needs than there is for eating according to your hair or eye colour.'

Food classifications

Foods are divided into those that are highly beneficial, those that are neutral, and those to avoid (poison to your type). The food lists are unnecessarily long and complicated, with detailed lists of the species of fish, meat, grains, drinks or cheeses allowed or not. It would be easy to become fanatical and not eat anything at all - which would account for the reports of weight loss. If you're O, the extra protein will no doubt help you shed weight, but so would another simpler high-protein way of eating.

D'Adamo seems obsessed with lectins, proteins found in legumes (which he claims are in all foods). If you eat the wrong food, the incompatible lectins ‘agglutinate blood cells near a target organ' and start to destroy it. He makes it sound scientific but it is contradictory - lectins do exist, but are generally destroyed during cooking and so are harmless.

Overall, while some of the diets are balanced, some are nutritionally deficient and would need supplements (which he also suggests). Often no real reason - apart from lectins - is given for why you'll lose weight eating one type of fish over another.

What you'll eat - see if it's for you

For blood type O

Breakfast

1 slice sprouted-wheat Essene bread * with apple butter
1 poached egg
green tea or herbal tea

Lunch
Grilled chicken breast with endive and tomato salad
1 slice rye bread
2 plums
Water or mineral water

Mid-afternoon snack
175ml vegetable juice
2 rice cakes with natural low sugar fruit spread

Dinner
Grilled steak
Bean salad
Steamed silverbeet tossed with lemon juice
Green tea or herbal tea

Avoid beer and wine

    * This is a heavy brick-like loaf made from spelt and ancient forms of wheat

Our rating

4 out of 10