Medium Chain Triglyceride (MCT) Diet


A diet often used in England and Canada, and select centers in the United States, is the MCT diet. MCT refers to the type of oil, medium chain triglyceride, used in the diet to make it more palatable. The approach is similar to the modified Atkins diet and low glycemic index treatment.

There are historically two main types of ketogenic diets used in practice.

Classical Ketogenic Diet

Medium Chain Triglyceride (MCT) Ketogenic Diet

  • The late Peter R. Huttenlocher MD is credited with creating the medium chain triglyceride (MCT) ketogenic diet in the 1970s. It has since been adapted and various versions are used in centers across the United Kingdom and Europe. It is used in the United States as well at select centers.
  • The MCT ketogenic diet uses a fat supplement that consists only of MCT fats (MCT oil). MCT fat can produce ketones more easily than LCT fat, and often does not require carnitine by the body (or as a supplement) to break down these fats into ketones. This means that in the MCT diet, less total fat is needed, thus allowing more carbohydrate and protein to be included in the regimen. It may also be more beneficial to the child or adult’s cholesterol and triglycerides than an LCT diet.
  • There are many ways to ingest MCT oil:
    1. It can be taken orally as MCT oil (available in stores and on the Internet without a prescription). Coconut oil is one example.
    2. Liquigen is a product made by Nutricia for children on ketogenic diets for epilepsy.
    3. Betaquik is a product made by Vitaflo/Nestle for children on ketogenic diets for epilepsy.
  • Find example MCT ketogenic diet recipes in Matthew's Friends Keto Kitchen.

The amount of energy given from MCT ranges between treatment centers. The original MCT diet described by Dr. Huttenlocher in the 1970s provided 60 percent of its calories from MCT. Due to tolerance issues using this amount of MCT, the diet was modified by Dr. Ruby Schwartz and colleagues in 1989 at Matthew’s Friends.

This modified MCT diet has 30 percent of the calories obtained from MCT oil or emulsion and 30 percent from long chain dietary fats. It has become known as the “John Radcliffe diet” because it was a product of the John Radcliffe hospital in Oxford, UK. The remaining energy breakdown was from carbohydrate, protein, and naturally occurring fat in foods.

Experience from the Institute of Child Health in London has shown that these levels may be too rigid, i.e., 30 percent of energy from MCT is too low to produce enough ketones, while 60 percent is too high as it may cause side effects. Each child responds differently to the MCT in the diet; thus the dietary prescription will vary from child to child. In many cases the level may begin at 40 percent but may need to be increased to 45-50 percent to maintain ketosis.

Toleration of the MCT Supplement

As with the classical diet, observed side effects, such as constipation, lack of energy, vomiting, abdominal discomfort and diarrhea, have been reported in the past. Chaffe et al (2005) assessed the side effects experienced by children on both the classical and MCT versions and found that no side effects were seen more frequently on either diet. Only 3 of the 54 children reviewed needed to discontinue the diet due to symptoms. In most cases, side effects on the MCT diet can be stopped by temporarily lowering the amount of MCT and re-introducing it gradually.

  • The MCT diet is traditionally more flexible than the classical version and a larger variety of food can be included due to the higher carbohydrate and protein allowance.
  • Most centers use exchange lists to divide up the allocated food groups for the day. Parents and caregivers have the flexibility of planning their own meals for the child by choosing foods from the lists in the allocated quantities.
  • Experience has shown that better ketone levels are reached and tolerance obtained if the MCT supplement is divided up evenly across the day between both snacks and meals, i.e., all food must be accompanied by a proportion of MCT fat.

Cereal Breakfast

  • Weetabix (A whole grain cereal that is not sugar coated)
  • Liquigen* & double cream (use like milk on the Weetabix)
  • Liquid sweetener
  • Cheese or ham on the side (for protein choices)

*Liquigen is a fractionated coconut oil used milk substitute in MCT diets.

Cooked Breakfasts

  • Bacon and/or egg
  • Mushrooms/tomatoes
  • Fried bread
  • MCT oil and ordinary oil or cream or Liquigen

Cooked breakfast notes:

  • You can make an omelet by adding some of the liquigen to it.
  • MCT oil is great for making fried bread and a very easy way of losing the fat.
  • You can make an ordinary fried breakfast and give the liquigen as a drink that is sweetened with liquigen sweetener and has some flavoring in it.

Toast Breakfast

  • Cheese on toast with liquigen to drink and some fruit.
  • Marmite on toast with butter. Liquigen and some cream, fruit, liquid sweetener blitzed up to make a fruit smoothie! You will probably have to add some cheese or ham to this breakfast for protein.
  • Sardines on toast – with one of the above fruit smoothies!
  • Liquigen mixes well with milk drinks, mashed vegetables, soups, casseroles, and desserts.
  • MCT oil can be used in baking, salad dressings, soups, and casseroles. It can also be used to lightly fry foods, especially foods that absorb oil well like mushrooms, tomato, aubergines, or marrow.
  • Care needs to be taken as MCT oil has a low smoke point, thus it cannot be heated excessively.
  • Full vitamin and mineral supplementation is recommended on the MCT diet.
  • The dietary prescription must be calculated by a registered dietitian who has experience in treating people with intractable epilepsy.
  • As with any ketogenic diet, once it has been started, it should be frequently reviewed as the MCT may need adjustment depending on tolerance and ketone levels.
  • Follow up visits to see the ketogenic team are scheduled after the diet has been initiated. At these visits height, weight, blood and urine tests are carried out to confirm that all is well and to ensure that any problems are detected early so that they can be acted upon.

In some cases, the MCT diet appears attractive to older children as the portion sizes are bigger and carbohydrates, such as potato, pasta, rice and bread, can be calculated into the diet in small portions.

In some cases, dietitians have found it useful to change a child from the classical version to the MCT if the child is becoming persistently resistant to eating the classical food at mealtimes. This change is dependent on the child then accepting the MCT supplement, which is an integral part of the MCT diet. The MCT diet can also be given in the form of a liquid feed and is thus suitable for gastrostomy tube-fed children. Many centers will use extra MCT oil as a supplement to the classic (LCT) ketogenic diet as well in order to improve efficacy and lipid profiles.

Authored By:

Nicole Edwards, registered pediatric dietitian

on Friday, February 04, 2022

Reviewed By:

Eric Kossoff MD

on Tuesday, August 21, 2018


Epilepsy Centers

Epilepsy centers provide you with a team of specialists to help you diagnose your epilepsy and explore treatment options.


Epilepsy Medication

Find in-depth information on anti-seizure medications so you know what to ask your doctor.


Epilepsy and Seizures 24/7 Helpline

Call our Epilepsy and Seizures 24/7 Helpline and talk with an epilepsy information specialist or submit a question online.


Tools & Resources

Get information, tips, and more to help you manage your epilepsy.


Find an Epilepsy Specialist

Ready for help? Find an Epilepsy specialist who can help guide you through your epilepsy journey.