The MCT Diet

In this edition of Ketogenic Diet News, we discuss a diet often used in England and Canada, yet seldomly used in the United States. The MCT diet, which refers to the type of oil (medium chain triglyceride), was designed to make the diet somewhat more palatable, in a manner similar to the recent modified Atkins diet and low glycemic index treatments (discussed in the April and May issues). I am pleased to have Nicole Edwards, an expert in the MCT diet from England, write this article.

Nicole Edwards is a registered pediatric dietitian who has specialized in the ketogenic diet for epilepsy. Nicole formerly worked at Great Ormond Street Hospital for Children NHS Trust, London, before moving to Hong Kong earlier this year. She has recently worked as a research dietitian for the ongoing ketogenic diet study that is being led by the Institute of Child Health and Great Ormond Street Hospital, London | Eric Kossoff, MD, Editor of Ketogenic Diet News

What is the MCT Diet?

There are historically two main types of ketogenic diets that are used in practice; the classical ketogenic and the medium chain triglyceride (MCT) ketogenic diet. The MCT diet, which was developed in the 1970s, has since been adapted and various versions are used in centers across the United Kingdom and Europe.

Normal dietary fats, which are used predominantly in the classical ketogenic diet, consist of a mixture of mainly long chain triglyceride (LCT) fats with a small amount of short and medium chain triglyceride (MCT) fats. Here are a selection of foods and recipes that you might see on the classical ketogenic diet. These are from the website of Matthew’s Friends.

Classical Breakfast Recipes

• Blueberry Muffins
• Egg Free Chocolate Muffin
• Keto Waffles

Classical Lunch / Dinner Recipes

• Cherry Tomato Omelet Served with Fennel
• Chicken and Avocado Salad followed by Rhubarb and Calogen
• Pizza
• Crispy Bacon and Brazil Nut Salad
• Stuffed Mushrooms
• Burgers with Onion Rings
• Fruit and Nut Omelet
• Panacotta

Classical Snack / Treat Recipes

• Keto Crackers
• Coconut Flapjacks
• Cookies

The MCT ketogenic diet uses a fat supplement which consists only of MCT fats. MCT fat can produce ketones more easily than LCT fat, which means that in the MCT diet less total fat is needed, thus allowing more carbohydrate and protein to be included in the regimen.

MCT Lunches / Dinners

• Garlic Chicken
• Chicken Casserole
• Beef Curry
• Lasagna
• Chili Pork Balls
• Shepherd's Pie

MCT Snacks / Treats

• Chocolate Brownies
• Keto Mince Pies

For example MCT fat comes in two forms; the first is a white, milky emulsion, manufactured by SHS International Ltd-Nutricia™. The second is MCT oil, which is clear and has a slightly thinner consistency than vegetable or olive oil. MCT oil is manufactured by SHS International Ltd-Nutricia™ and Novartis™.

Peter R. Huttenlocher, MD, Professor of Pediatrics and Neurology and a Member of the Committee on Neurobiology at the University of Chicago since 1976, is credited with creating this diet.

How much MCT is needed in the diet?

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 and 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.

What is the diet like?

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.

Here are some breakfast ideas:

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)

Cooked Breakfasts:

• Bacon and/or Egg
• Mushrooms/Tomatoes
• Fried Bread
• MCT Oil and ordinary oil or Cream or Liquigen, a fractionated coconut oil used milk substitute in MCT diets

You can make an omelet 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 – sweetened with liquigen sweetener and 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 as well for protein.
• Sardines on Toast – with on 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, casseroles and can also be used to lightly fry foods, especially ones which absorb oil well for example 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, however calcium supplementation would not be necessary if the diet allowed adequate milk to meet the child’s daily calcium requirements.

How is the diet initiated and monitored?

The dietary prescription must be calculated by a registered dietitian who has experience in treating patients 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.

Who might the diet help?

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 is of course 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.

A study evaluating the MCT vs. LCT diets, with a randomized protocol and “placebo” (waiting period) of 1-4 months, is nearing completion at Great Ormond Street Hospital in London by Dr. Helen Cross, PhD, Reader and Honorary Consultant at Paediatric Neurology Institute of Child Health & Great Ormond Hospital NHS Trust, London). Dr. Eric Kossoff will bring epilepsy.com the results.

References:

• Chaffe HM, Neal EG, Schwartz RH, Lawson M, Cross JH. Side effects of the ketogenic diet for intractable epilepsy: A review of a parental questionnaire at 3 months on the diet. Epilepsia, 2005, 45, Suppl. 8:227 (abst. 2.401)
• Huttenlocher PR, Wilbourn AJ, Signore JM. Medium Chain Triglycerides as a therapy for intractable childhood epilepsy. Neurology, 1971, 21 1097-103
• Neal EG, Chaffe HM, Lawson M, Schwartz RH, Cross JH. Use of the ketogenic diet to treat childhood epilepsy – a randomised controlled trial. Arch Dis Child, 2004, 89 (Suppl) A5.
• Schwartz RH, Eaton J, Bowyer BD, Aynesley Green A. Ketogenic diets in the treatment of epilepsy: short-term clinical effects. Dev Med Child Neurol, 1989, 31 145-51.