Ketogenic Diet

Ketogenic Diet


The ketogenic diet, or keto diet, has been used for nearly 100 years to help people with epilepsy control their seizures. The keto diet is being studied for a number of other conditions including Alzheimer’s disease, brain cancers and weight loss. 

Because this diet is very low in carbohydrates or carbs, your body burns fat for energy. This is called ketosis. Ketosis also happens in your body when you haven’t eaten for a long time. If you follow a keto diet, fat cells go to your liver where some are broken down and some are stored as ketones. 

It can take time for your body to adjust to using ketones and fat for energy, instead of carbs. You may feel weak, tired and even like you have mild, flu-like symptoms. These signs often last a few days or until your body goes into ketosis and adjusts to using fat for energy. 

Talk with your doctor or dietitian to see if you may benefit from following a keto diet or if you have other questions.

Types of keto diets

There are 5 different types of the keto diet. The 3 types most often used are: 

  • Classic Keto
  • Modified Atkins
  • Low Glycemic Index Treatment (LGIT)

More details and sample menus for each of these diets are included in this handout for your review.

The other types of keto diet are used less often and include:

  • Modified Keto – This type is still very limited, but it allows slightly more protein and carbohydrates than Classic Keto.
  • Medium Chain Triglyceride (MCT) – Half of the fat comes from a special fat, called MCT, that causes many stomach and intestinal side effects, so it is not very popular.

With all keto diets, drinks are limited to:

  • Sugar free beverages, such as water, sugar-free seltzer water, tea and coffee (with the option to add real cream).
  • High salt beverages, such as beef, chicken or vegetable broth. These are also good to drink, so you get enough salt, called sodium, in your body.

Classic Keto

  • This is the original keto diet used to treat epilepsy. 
  • Most limited type that requires food to be carefully measured on a gram scale. A scale can be purchased at many stores that carry cooking supplies.
  • Most of the calories (90%) come from fats. There are lower proteins and very low carbohydrates in this type compared to the other types of keto diets.
Classic Keto sample menu

Modified Atkins

  • This diet has less calories from fat (60%). It is still low in carbohydrates, but does not limit protein as does the classic keto diet.
  • This diet is often easier to follow since food does not have to be measured on a gram scale.  
  • Most people start off on this diet to get into ketosis.
Modified Atkins sample menu

Low Glycemic Index Treatment (LGIT)

  • This diet has less restrictions than the other types.
  • This diet is meant to mimic a state of ketosis, but does not actually put a person in ketosis. The LGIT diet can help with seizure control but less than the other types of keto diets.    
  • This diet only allows foods with a glycemic index (GI) of less than 50.
LGIT sample menu

Grams of fat, carbohydrate and protein in each type of diet

Grams of fat, carbohydrate and protein in each type of keto diet

For more information and recipes

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© 2018 - October 15, 2021, The Ohio State University Wexner Medical Center

This handout is for informational purposes only. Talk with your doctor or healthcare team if you have any questions about your care. For more health information call the Library for Health Information at 614-293-3707 or email: