II was at a party sitting with a group of people.  We were discussing diets.  One person commented, ‘I’ve got to get onto that eat by your blood type diet’.  Another person said, ‘I agree, I’ve heard that that diet really works’.  The blood type diet is one that has been going around for a while and the premise is that the different blood types require different foods to eat to lose weight.  What is the science behind this diet and does eating by your blood group work?


Blood Type Diet


Blood type O has a diet high in protein and low in legumes and grains.  A meat free diet based around fruit and vegetables, legumes and grains is characteristic of Blood type A .  Blood type B has a diet high in green vegetables eggs, certain meats and low fat dairy.  A diet high in green vegetables, seafood and dairy is characteristic of Blood type AB.


Researches Studied Participants Dividing Them Into The Blood Type


Canadian researchers took 1,455 subjects (993 women and 462 men) from the Toronto Nutrigenomics and Health (TNH) Study, a study of adults aged 20 to 29.

They divided the group into the four blood types and determined their blood group using a technique called genotyping.  They assigned a diet based on the blood type diet to each of the groups.    

The researches recorded BMI and waist circumference to determine how much fat each individual was carrying.  They also measured various markers of health.  This included triglycerides, free fatty acids, glucose, insulin, and cholesterol levels measured before and after eating from the diet.

What the researchers found was that there were definitely improvements in health and weight.  However there was no relationship with health and weight and what blood type diet the participants were on.   


What Does the Research Tell Us?

What this means is that eating by your blood type, or the blood type diet, does not influence your health any more than healthy eating.  Eating healthy is required for long term health maintenance and it is recommended that getting in your 5 serves of veges, 2 serves of protein, and 2 servings of fruit will see you living a healthy life. 



Wang, J, Nielsen DE, El-Sohemy, A, ‘ABO Genotype, ‘Blood-Type’ Diet and Cardiometabolic Risk Factors’, PLoS One. 2014; 9(1): e84749

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