The Blood Type diet is based on the idea that you should choose your food according to whether you're in group 0, A, B or AB. Our diet plan review explains the theory behind this eating plan.

Naturopath Dr Peter D'Adamo claims the Blood Type diet can help you lose weight, lower your risk of disease and feel healthier, and celebrities including Courtney Cox-Arquette, Liz Hurley and Martine McCutcheon have signed up to his diet meal plans. However, nutritionists say there is no medical evidence that the Blood Type diet works.

Dr D'Adamo believes that the body of someone who is Group 0 will deal with nutrients differently to someone who is Group A. Each group has, according to D'Adamo, a unique antigen marker, and this reacts badly with certain foods, causing potential health problems. D'Adamo also claims that levels of stomach acidity and digestive enzymes are also determined by this antigen marker. He claims diet meal plans and recipes designed for your own antigen marker will help your body digest and absorb food more efficiently, so that you lose weight.

His theory claims that because the 0 group evolved earlier than the A and B group, if you belong to the 0 group you should eat the same food your ancestors ate 50 000 years ago when they were hunter-gatherers, namely lots of protein-rich meat. Group A evolved around 15 000 BC when our ancestors had become farmers, so group A should eat a vegetarian diet. Group B evolved in 10 000 BC when our ancestors became nomads, so can eat a varied diet including meat, dairy, vegetables and grains. Group AB evolved 1 000 years ago, so people in the AB group can eat a mixture of the food suitable for group A and group B.