They found that people who follow such diets have a significantly increased risk of developing heart disease, LDL cholesterol buildup, kidney failure, Alzheimer's disease, diabetes, and cancer. They also discovered that keto diets are particularly dangerous for people who are currently pregnant or may become pregnant. Low-carbohydrate diets are linked to birth defects, particularly neural tube defects, and gestational diabetes even if the pregnant person is taking folic acid supplements. Additionally, for those living with chronic kidney disease (CKD), the high amounts of protein consumed on the keto diet can place excess stress on the kidneys and worsen the long-term internal damage of CKD.

So why does this diet have such negative side effects? The study’s authors suggest that it has to do with the nutrient quality of the food being eaten.

"The foods that are emphasized on a keto diet are the very products that cause colon cancer, heart disease, and Alzheimer’s disease," says study co-author Neal Barnard, MD, FACC, president of the Physicians Committee for Responsible Medicine and an adjunct professor of medicine at George Washington University School of Medicine. “New research also shows that these same foods raise the risk for severe COVID-19

This sentiment is echoed by lead review author Lee Crosby, RD. “The typical keto diet is a disease-promoting disaster,” says Crosby. “Loading up on red meat, processed meat, and saturated fat and restricting carbohydrate-rich vegetables, fruits, legumes, and whole grains is a recipe for bad health.”<