There is little doubt that you’ve at least heard of the keto diet, or ketogenic diet, which challenges dieters to consume a very low-carb, high-fat diet and protein-rich. While keto may seem linked to many health benefits (i.e., fast weight loss), the diet has also been linked to a few negative side effects. Many don’t realize that the keto diet has long been recommended for patients with diabetes, cancer, and epilepsy. However, just because it helps you lose weight, doesn’t mean keto is for everyone for the following reasons:

1. Ketosis isn’t for everyone

The purpose behind the keto diet is to put the body in a state known as ketosis, or fat burning mode. Most dieters do this by adapting to an eating regimen that focuses on high protein and high fat foods like cheese, eggs, meat, fish, dairy, and poultry while significantly restricting high carb foods such as breads, pasta, potatoes, legumes, carrots, and of course, alcohol, and refined and natural sugars. In the end, participants reach ketosis by limiting carbs to just 5% while fat and protein intake is boosted to 75% and 20%. So while the pounds are coming off with keto some people have reported negative and uncomfortable side effects.

2. Kidney issues

Due to the very restrictive rules around keto (and carbohydrate consumption) some keto devotees experience pretty severe dehydration and electrolyte imbalances, which may negatively affect the kidneys in several ways. For instance, as the brain readjusts to metabolizing ketones for energy (from fats) versus carbohydrates, the kidneys produce more electrolytes as insulin levels decrease. This may lead to chronic constipation, fatigue, and nausea due to low functioning kidneys, and perhaps eventual kidney damage.

3. Weight loss with consequences

All in all, most nutritionists agree that the human body isn’t equipped to deal with a diet that’s so severely restrictive. So while you may experience impressive weight loss results over what seems a quick period of time, many health professionals warn of the keto flu. According to doctors from Manhattan Cardiology in New York City, the keto flu ushers in a combination of chronic malaise, irritability, brain fog, migraines, and nausea within the first few months on the diet, which can impact healthy work, exercise, and social life.

4. Cardiovascular dangers

In the end, a diet as restrictive as keto should be supervised by a medical doctor to ensure the patient does not’ suffer malnourishment (from nutritional deficiency) and several known heart health risks. After all, keto is full of foods we were long warned to limit for fear of cardiovascular health reasons (i.e., red meats like steak and bacon) which are high in saturated fats, triglycerides, and LDL (bad) cholesterol, and linked to heart attack and stroke.