Blood type doesn’t affect the health benefits of a vegan diet, says the study. The research was published in the Journal of the Academy of Nutrition and Dietetics. In this trial, researchers compared participants (who followed a plant-based and those who made no dietary changes) weight, cholesterol levels, and body composition. They found no difference in these health outcomes among blood types A, B, or O. 

People who followed a plant-based diet improved their metabolism as assessed by an increase in after-meal calorie burn, which was 18.9 percent on average, while compared to the control group.

Hence, these results suggest the blood type was not linked to a plant-based diet’s effects on body fat, body weight, glycemic control, or plasma lipid concentrations. The researchers say that there is no scientific reason to restrict the potential health benefits of a plant-based diet for chronic disease prevention and treatment of blood type.

Defenders of the blood type diet claimed that people who have Type A blood might benefit from a vegan diet. On the contrary, a recent study discovered that there is no connection between blood type and a vegan diet. The scientists recommend that plant-based diets are more healthy for all blood types.

To lead a healthy life you should exercise and follow a nutritious diet. According to the (CDC) Centers for Disease Control and Prevention, people should follow a balanced diet of veggies, fruits, lean meat, and poultry. The blood type diet recommends that nutritional requirements depend on a person’s blood type.

Debunking the Blood Type Diet

The blood type diet is an individual’s eating patterns to particular food items to increase the health benefits. But, in 2013, a review was published in The American Journal of Clinical Nutrition that stated that these findings required scientific evidence.

However, the result did not confirm that people on a Type A diet who eat a high amount of fruits, grains, and vegetables might have a lower body mass index(BMI) and waist circumference, decreased blood pressure, fat, and cholesterol. These improvements in risk factors were not based on blood type.

Hence, there is no sufficient evidence to support blood type diets, some people consider that catering to blood type may decrease disease risk.

Purpose of the Study

The new study in JAMA Network Open discovered that low-fat vegan diets helped to decrease insulin resistance and increased metabolism, which helped weight management. Based on these outcomes, scientists associated with the Physicians Committee for Responsible Medicine restudied the research’s data to find whether blood type played a vital role.

The present study was conducted with an intervention group in the 16-week trial. This study was published in the Journal of the Academy of Nutrition and Dietetics.


The trial was conducted with a total of 244 people (both men and women) from Washington. D.C. These participants did not have any history of drug abuse, diabetes, lactation, or pregnancy, and no one used to follow a plant-based diet.

The scientists asked half of the participants to follow a clean, low-fat vegan diet, and the rest were assigned to follow their usual diet without any changes. The participants self-reported their health experiences and what they ate throughout the 16-week trial.

The vegan group also took part in weekly dietary classes that health professionals led. Researchers suggested to all participants to follow their regular exercise activities.

The measurement of cardiometabolic risk factors was examined at the beginning and end of the trial, followed by 10-12 hour overnight fasting with water.


At the beginning of the trial, the low-density lipoprotein (LDL) cholesterol levels and body weight were higher in participants with blood Type A than those with other blood types. On the contrary, body weight and LDL cholesterol level were lower in participants with blood type O than those with different blood types. 

There were no many differences between blood type and the changes that came out of the plant-based diet.

After 16 weeks, there was no significant change in body weight between the blood type groups on the low-fat vegan diet. The average weight loss of blood type O is 7.1KG, and those with other blood types are 6.2 KG.

Scientists concluded that there is no evidence to show the difference in the decrease in average cholesterol between the groups. 

The scientists concluded by stating, “Although the intervention diet was similar to that recommended by D’Adamo [a proponent of the blood type diet] for individuals with blood type A and specifically recommended against for those with type O, there were no associations between these blood types and the outcomes of the dietary intervention.”