Overview

The ketogenic diet is a high-fat, very low-carb diet. It usually limits carbs to 20-50 grams daily. This forces the body to break down fat for energy.

The body breaks down fat into molecules called ketone bodies. These ketone bodies can be used for energy. The classic ketogenic diet, which is used to reduce seizures in children, requires up to 4 times as many calories from fat as from carbohydrate and protein.

A very strict form of the ketogenic diet is used for seizure disorders in people with hard-to-treat epilepsy. Less strict forms of the ketogenic diet are used for obesity and diabetes. Ketogenic diets are also used for migraine headaches, Parkinson disease, polycystic ovary syndrome (PCOS), and many other conditions, but there is no good scientific evidence to support many of these uses.

Don't confuse the Modified Atkins Diet, a type of ketogenic diet, with the Atkins diet. Also don't confuse the ketogenic diet with "Keto diet pills." These are not the same and don't have the same effects.



Uses & Effectiveness

Possibly Effective for

  • Diabetes. Following a ketogenic diet seems to improve blood sugar control in people with type 2 diabetes.
  • Seizure disorder (epilepsy). A strict ketogenic diet that is high in fat and very low in carbohydrates can reduce seizures in some people with hard-to-treat epilepsy.
  • Obesity. Following a ketogenic diet that limits carbohydrate intake to less than 50 grams daily can reduce body weight by 10% to 30% in 1 year. But it's not clear if it works better than other diets that limit calorie intake.

There is interest in using ketogenic diet for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: The ketogenic diet is likely safe for most adults when used for up to 1 year. The most common side effects include constipation, fatigue, dizziness, headache, weakness, nausea, diarrhea, and stomach pain. The long-term safety of the ketogenic diet in adults is unknown. It is important to ensure any diet remains balanced and contains nutrient-rich foods.

Special Precautions and Warnings

When taken by mouth: The ketogenic diet is likely safe for most adults when used for up to 1 year. The most common side effects include constipation, fatigue, dizziness, headache, weakness, nausea, diarrhea, and stomach pain. The long-term safety of the ketogenic diet in adults is unknown. It is important to ensure any diet remains balanced and contains nutrient-rich foods.

Pregnancy: There isn't enough reliable information to know if the ketogenic diet is safe when pregnant. Ketone bodies are chemicals made in the body when people follow a ketogenic diet. There is some concern that these chemicals might pass to the baby and slow down growth during pregnancy and after birth. Don't follow this diet unless under the care of a healthcare professional.

Breast-feeding: The ketogenic diet is possibly unsafe when breast-feeding. Following a very-low carbohydrate ketogenic diet when breast-feeding might increase the risk for a serious health issue called ketoacidosis. Don't follow this diet unless under the care of a healthcare professional.

Children: The ketogenic diet is possibly safe when used by children under the care of a doctor, short-term. There is some concern about the ketogenic diet when used long-term. When used for more than 2 years, the ketogenic diet has been linked with slowed growth, fractures, and kidney stones in children.

Heart conditions: Use with caution. The ketogenic diet might worsen certain heart conditions.

Diabetes: Following a very-low carbohydrate ketogenic diet might increase the risk for diabetic ketoacidosis (DKA), a serious complication of diabetes. If you have diabetes, speak with a healthcare professional before starting the ketogenic diet.

Acid reflux: Some ketogenic diets are high in fat. High-fat diets can worsen symptoms of acid reflux.

High levels of fat in the blood: Some ketogenic diets are high in fat. Diets high in fat can increase levels of cholesterol and other fats called triglycerides. This might be a problem for people who already have high levels of these fats in the blood. Talk to your doctor before starting the ketogenic diet.

Liver disease: The ketogenic diet might cause liver injury and may worsen symptoms of liver disease.

Problems breaking down fats in the diet: The ketogenic diet forces the body to break down fat for energy. For people unable to break down fat, the ketogenic diet might lead to serious adverse effects, including coma or death.

Kidney disease: The ketogenic diet may worsen kidney disease and has been linked with kidney stone development.

Weak and brittle bones (osteoporosis): Long-term use of the ketogenic diet may weaken the bones. Use caution if you are at risk for or have a history of osteoporosis.

Swelling (inflammation) of the pancreas (pancreatitis): The ketogenic diet may increase the risk of developing pancreatitis. Use caution if you have a history of pancreatitis or have very high triglyceride levels.

Surgery: Certain medications used during surgery contain carbohydrates. Talk to your healthcare provider before any surgery if you are using the ketogenic diet to reduce seizures. Changes to some medications used during surgery might be needed.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Medications for diabetes (Antidiabetes drugs) interacts with Ketogenic diet

    The ketogenic diet might lower blood sugar levels. Following the ketogenic diet while also taking diabetes medications might cause blood sugar to drop too low. Monitor your blood sugar closely.

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with Ketogenic diet

    The ketogenic diet might slow blood clotting. Following the ketogenic diet while taking medications that also slow blood clotting might increase the risk of bruising and bleeding.

  • Medications used to prevent seizures (Anticonvulsants) interacts with Ketogenic diet

    The ketogenic diet might reduce blood levels of some medications used to prevent seizures. This might lower the effects of these medications and increase the risk of seizures. Levels of medications used to prevent seizures should be monitored in people starting the ketogenic diet.

  • Medications used for seizures and glaucoma (Carbonic anhydrase inhibitors) interacts with Ketogenic diet

    Some medications used for seizures and glaucoma can increase the risk of kidney stones. The ketogenic diet might also increase the risk of kidney stones. Following the ketogenic diet along with these medications might increase the risk of kidney stones.

  • Valproate interacts with Ketogenic diet

    Taking valproate might increase the risk of side effects in some people following the ketogenic diet. But this is rare.

  • Medications for diabetes (SGLT2 Inhibitors) interacts with Ketogenic diet

    Following the ketogenic diet while taking an SGLT2 inhibitor, a type of diabetes medication, increases the risk of a serious complication called ketoacidosis. If you are taking these medications, speak with your healthcare provider before starting a ketogenic diet.

Dosing

The classic ketogenic diet requires 90% of daily calories to come from fat. But there are many other, less restrictive versions of the ketogenic diet that typically allow 20-50 grams of carbs daily. Variations include the medium chain triglyceride diet, modified Atkins diet, modified Mediterranean diet, and low glycemic index treatment. Speak with a healthcare provider to find out which variation of the ketogenic diet might be best for a specific condition. The ketogenic diet isn't suitable for everyone.
View References
Show More Show Less

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is licensed from Therapeutic Research Center, LLC. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
Licensed from Therapeutic Research Center, LLC
Copyright © 1995-2025 by Therapeutic Research Center, LLC. All Rights Reserved.