Dr. Kim Williams, the past President of the American College of Cardiology, said no one should be doing a ketogenic diet - unless short term weight loss is more important than their health. Low-carbohydrate diets are associated with a significantly higher risk of all-cause mortality.1 Ketogenic diets may also have adverse side effects such as kidney stones, impaired growth, osteoporosis, and hyperlipidemia 2,3 in the long term. In other words, the short-term benefits of these diets generally do not outweigh their long-term risks.
A 2013 systematic review that sifted through 1,415 studies determined that there is not even one credible study establishing benefits of a blood type diet. In 2014, a study that evaluated nearly 1,500 people found that regardless of blood type, following a type A diet (predominantly plant-based diet) was associated with better overall cardiometabolic health.