The ketogenic diet, also known as the ketogenic diet or simply keto, has become a popular weight loss plan recently promoted by celebrities. It consists of reducing carbohydrates to 50 grams a day or less, to help the body achieve a state of ketosis, in which it has to burn fat (instead of sugar) for energy. While this diet can be effective for weight loss, it also has some potential drawbacks. One of the main disadvantages of the ketogenic diet is that it eliminates many nutrient-rich foods, such as whole grains, beans, fruits and vegetables.
This can lead to nutrient deficiencies and constipation. Additionally, people on the ketogenic diet may experience short-term side effects such as fatigue, headache, mental confusion and upset stomach, also known as “keto flu”. Long-term health risks include kidney stones, osteoporosis and liver disease. Diarrhea is another common side effect of the ketogenic diet.
This can be due to a lack of fiber in the diet or an intolerance to dairy or artificial sweeteners. People with type 1 or type 2 diabetes should not follow the ketogenic diet without their doctor's permission and close supervision, as it can trigger a dangerous condition called ketoacidosis. Symptoms of ketoacidosis include dry mouth, frequent urination, nausea, bad breath and breathing difficulties; if you experience them while on the ketogenic diet, see a doctor immediately. Health experts say that the ketogenic diet is not an adequate plan to follow in the long run.
A study presented at the Congress of the European Society of Cardiology in Munich suggested that people who followed the lowest carbohydrate diets had the highest risk of dying from cancer, cardiovascular disease and all other causes. Another study published in The Lancet found that people who followed diets that were low in carbohydrates and high in animal protein had a higher risk of premature death compared to those who consumed carbohydrates in moderation. Most people who have tried this diet report initial symptoms of bad breath, headaches, muscle cramps, nausea and constipation, which are collectively known as the “ketogenic flu”. Doctors recommend restricting the diet to 3-6 months, with a gradual progression to a Mediterranean or plant-based diet.
The popular ketogenic diet plan generally requires a person to modify their diet to contain 5% carbohydrates, 20% protein and 75% fat. Following the ketogenic diet eliminates most fruits and many starchy vegetables due to their high carbohydrate content. The ketogenic diet may be helpful in treating epilepsy — it's not clear exactly why, but there's something about the ketogenic state that seems to reduce the frequency of seizures. It can also result in weight loss when compared to a typical Western diet that is high in ultra-processed foods but low in fiber.
However, doctors say that people with kidney disease, diabetes, heart or bone disease or other medical conditions should talk to their healthcare provider before trying the ketogenic diet.