A new in-depth review has found that ketogenic (or keto) diets may do more harm than good for many people, especially those who are pregnant or have kidney disease.
While keto diets have become popular for weight loss and managing certain health conditions, researchers now warn that this way of eating can increase the risk of several serious diseases and is not safe for long-term use.
The study, published in Frontiers in Nutrition and led by Lee Crosby and her team, is the most comprehensive analysis of keto diets to date. The review examined how keto diets affect a wide range of health outcomes, including heart disease, cancer, diabetes, brain health, kidney function, and pregnancy.
A typical keto diet is very low in carbohydrates, moderate in protein, and high in fat. This combination is meant to put the body into a state called ketosis, where it burns fat instead of carbs for energy.
While this can result in quick weight loss, the study found that these effects are not more effective than other diets in the long term. And the potential health risks may outweigh any short-term benefits.
The researchers raised strong concerns about the health impact of eating large amounts of red meat, processed meats, and saturated fat—foods commonly found in keto diets.
At the same time, the diet limits healthy carbohydrate-rich foods like fruits, vegetables, legumes, and whole grains. These plant foods are linked to lower risk of chronic diseases and play a vital role in a balanced diet.
For pregnant women or those planning to become pregnant, the keto diet may be especially dangerous. The review found that low-carb diets are linked to a higher risk of birth defects, particularly neural tube defects, even when the mother takes folic acid.
This suggests that cutting out key foods during pregnancy can have serious consequences for the baby’s development.
People with kidney disease are also at risk. High-protein versions of the keto diet may speed up the loss of kidney function and increase the chance of kidney failure.
Another concern is the effect of keto diets on cholesterol. Many people following a keto diet experience a rise in LDL cholesterol—the “bad” cholesterol linked to heart disease. The researchers point out that while some may lose weight on keto, the diet may raise their risk of heart problems, cancer, type 2 diabetes, and even Alzheimer’s disease in the long run.
The review also found that many of the health conditions keto diets are supposed to help—including fatty liver disease, type 1 and type 2 diabetes, and Alzheimer’s disease—could actually be worsened by the typical high-fat, animal-based keto diet. Foods commonly eaten on the diet have been linked to the very diseases the diet is promoted to fight.
According to the researchers, the only well-supported medical use of the keto diet is in reducing seizures in people with drug-resistant epilepsy. Outside of that, there is little evidence to suggest the diet is safe or more effective than other options.
In conclusion, while the keto diet may appear appealing for quick weight loss or other health claims, this review suggests that the risks may be too high for many people—especially pregnant women, kidney disease patients, and those concerned about heart and brain health.
Instead, a balanced diet that includes a wide range of fruits, vegetables, whole grains, and lean proteins is likely to be a safer and more sustainable path to good health.
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