Ketogenic (keto) diets pose substantial health risks that may outweigh their benefits, at least based on the way most people follow these diets, according to a new research review published in the journal Frontiers in Nutrition.
What’s more, the review authors wrote, people with certain health conditions — including people with kidney disease, and pregnant women — may be at higher risk than the general population for poor health outcomes linked to typical keto diets. A “classic” keto diet is a very-low-carbohydrate diet that is especially high in fat, with a modest protein component. This balance of components is meant to induce ketosis — the production of ketones as an alternative fuel source to glucose. Urine levels of ketones are often used as a way for people who follow a keto diet to follow how well their diet is maintaining ketosis.
For many people who follow a keto diet, the goal of ketosis is to lose weight. But keto diets have also been promoted for other health conditions, including diabetes and seizure disorders. But keto diets typically involve eating large quantities of foods that may promote chronic diseases, even if they result in some immediate or short-term benefits, according to the review authors.
Keto dangers for pregnant women, those with CKD
As noted in a press release on the review, one key finding is that keto diets may be unsafe for women who are or may become pregnant, due to an increased risk for neural tube defects in the baby — even when the woman takes folic acid as a supplement. Higher-protein versions of keto diets may also shorten the time to kidney failure in people with chronic kidney disease (CKD) — a concern that may apply especially to people with diabetes, who may benefit from better blood glucose control on a keto diet but are also at higher risk for kidney disease.
The review authors also noted that keto diets may raise LDL (low-density lipoprotein, or “bad”) cholesterol levels in many people due to a high intake of animal-based fats. Another major concern is that severely restricting carbohydrates almost inevitably means shifting a person’s diet away from a wide variety of plant-based foods, which are the source of an enormous range of beneficial nutrients including fiber, vitamins and minerals, and phytonutrients like flavonoids — all of which can reduce the risk of chronic diseases like cancer, heart disease, diabetes, and dementia.
“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,” said study author Lee Crosby, RD, nutrition education program manager at Physicians Committee for Responsible Medicine, in the press release. “In addition to the significant risks to kidney disease patients and pregnant women, keto diets are risky for others, too, as these diets can increase LDL cholesterol levels and may increase overall chronic disease risk.”
Want to learn more about the keto diet and diabetes? Read “Keto Diet for Diabetes: Help or Hindrance?” and “Ketoacidosis vs. Ketosis: What’s the Difference?”