“What Are Ketones Anyways?”

When your child is on the medical ketogenic diet for seizures, the word “ketone” is a part of your everyday vocabulary. Not only do you talk about them, chances are that you measure them regularly as well. Despite this, you may find yourself wondering, “What are ketones anyways?”

Ketones, sometimes referred to as “ketone bodies”, are water-soluble compounds (meaning that they dissolve in water) that are produced as “byproducts” when the body burns fat for energy [1]. Normally, the body produces only small quantities of ketones but ketone production increases when the body is using fat as a primary source of fuel. This happens during starvation, when the liver burns stored body fat for energy, and on a ketogenic diet, when the liver burns large quantities of dietary fat for energy.

As the liver burns fat, ketones build up in the blood and the body is said to be in “ketosis”.  Ketones are transported from the liver through the blood to the brain, heart, and skeletal muscles where they can be used for energy[2].

Types of Ketones:

There are 3 different types of ketones: beta-hydroxybutyrate, acetoacetate, and acetone. Beta-hydroxybutyrate and acetoacetate are the most abundant ketones[3]. Acetone is produced in much smaller quantities, making up just a small proportion of the total ketone levels. While beta-hydroxybutyrate and acetoacetate are transported through the blood to provide energy to other parts of the body, acetone is not. Instead, it is exhaled through the lungs, which is why individuals on the medical ketogenic diet may have a characteristic smell to their breath.

Measuring Ketones:

When the body is in ketosis, ketones can be detected in the blood, urine and even in the breath.

Health care providers typically measure a patient’s ketone levels using blood or urine tests. Blood tests measure the blood levels of beta-hydroxybutyrate specifically. Urine tests, on the other hand, measure the levels of acetoacetate primarily. Although blood tests are generally viewed as more reliable measures of ketosis, urine testing is more practical for caregivers. Health care providers may use blood tests to evaluate ketone levels during diet initiation and at follow-up appointments but most families will measure ketones at home using urine test strips. Ketones can also be measured in the breath, although this is not a commonly used method [4, 5]. Breath testing of ketones specifically measures the level of acetone exhaled.

The Role of Ketones in Seizure Control

Because ketones can pass through the blood-brain-barrier, they are able to enter the brain to provide fuel[1]. There are many theories about how the ketogenic diet works to reduce seizures. One theory is that the ketones have an antiepileptic effect on the brain. However, we still don’t know exactly what role ketones play. Although ketone levels are good indicators that the body is in ketosis, the level of ketones do not always correlate with the degree of seizure control[6]. In other words, some individuals may have high levels of ketones but poor seizure control while others have low ketones but good seizure control. Because of this, some researchers believe that ketone levels may just be a sign that the body is in ketosis and that perhaps there is some other factor associated with ketosis that is responsible for the effect on seizures.

  1. Kossoff, E.H., et al., Ketogenic Diets: Treatments for Epilepsies and Other Disorders. Fifth ed. 2011, New York, NY: Demos Medical Publishing.
  2. Nelson, D.L. and M.M. Cox, Lehninger Principles of Biochemistry. Third ed. 2000, United States of America: Worth Publishers.
  3. Qiao, Y., et al., Breath ketone testing: a new biomarker for diagnosis and therapeutic monitoring of diabetic ketosis. Biomed Res Int, 2014. 2014: p. 869186.
  4. Musa-Veloso, K., S.S. Likhodii, and S.C. Cunnane, Breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals. Am J Clin Nutr, 2002. 76(1): p. 65-70.
  5. Musa-Veloso, K., et al., Breath acetone predicts plasma ketone bodies in children with epilepsy on a ketogenic diet. Nutrition, 2006. 22(1): p. 1-8.
  6. Danial, N.N., et al., How does the ketogenic diet work? Four potential mechanisms. J Child Neurol, 2013. 28(8): p. 1027-33.

Medium Chain Triglcyerides (MCTs) and the Ketogenic Diet

coconutoilIf you are new to the ketogenic diet, you may be wondering about the term “MCT” you keep hearing about. MCT stands for medium chain triglyceride. Some of you may already be using MCTs, but perhaps you are wondering what makes them different from regular fats and oils. In today’s post, we’ll teach you all about MCTs, what makes them unique, and how they are sometimes used with the ketogenic diet for epilepsy.

Dietary Fat

To understand MCTs, it helps to know a little about dietary fat in general.  Dietary fat is made up of fatty acids, often referred to as the “building blocks” of fat. Fatty acids can classified as short, medium, or long-chain, depending on their length.

Most of the fat in the foods we eat is in the form of triglycerides, which are made up of 3 fatty acids. A triglyceride can be classified as short, medium, or long-chain depending on the length of the fatty acids that it contains. A long chain triglyceride (LCT) contains 3 long chain fatty acids, a medium chain triglyceride (MCT) contains 3 medium chain fatty acids and a short chain triglyceride (SCT) contains 3 short chain fatty acids.

How the Body Processes MCTs

Now that you understand the structure of dietary fat, let’s move on to the differences in how the body processes MCTs in comparison to LCTs.

  1. Digestion & Absorption: Because of their shorter length, MCTs are more easily digested and absorbed in the gastrointestinal tract than LCTs.
  2. Transportation: Once dietary fat is absorbed by the gastrointestinal tract, the body must then transport it to the liver where it is metabolized to produce energy. MCTs are transported directly from the gastrointestinal tract through the bloodstream to the liver.  In comparison, LCTs must take a longer route through the lymphatic system then through the circulatory system before finally reaching the the liver. The analogy I like to use is that LCTs and MCTs have the same origin (GI tract) and destination (liver) but LCTs take the longer, slower scenic route and MCTs take the expressway.
  3. Metabolism: In addition to the differences described above, the metabolism of MCTs is unique as well. Fat metabolism occurs in the mitochondria of the liver. LCTs require a substance called carnitine to enter the mitochondria, however MCTs can enter mitochondria freely so they are not limited by the presence of carnitine.

How Is MCT Used with the Ketogenic Diet?Liquigen

Remember that the ketogenic diet works by switching the body’s metabolism from using glucose for energy to using fat for energy, which produces high amounts of ketones in the body. The unique features of MCTs make it useful with the ketogenic diet because MCTs are capable of producing more ketones than regular fat (which is mostly LCT). Although a small number of foods contain a percentage of MCTs (such as coconut oil, palm kernel oil, and butter fat), pure MCT oil is not found naturally. However, there are specially-produced MCT oils available, such as Liquigen®.

The MCT Ketogenic Diet (MCTKD) was first introduced in the 1970s. This diet is a variation of the Classical Ketogenic Diet and is based on the percentage of calories coming from MCTs (usually between 30-60%), rather than a ketogenic ratio. The idea is that because MCTs produce more ketones than regular fat (which consists of mostly LCTs), incorporating high amounts of MCTs into the diet allows patients to stay in ketosis while consuming relatively higher amounts of protein and carbohydrates. This makes the MCTKD appealing to individuals who might have trouble complying with the protein and carbohydrate restrictions of the Classical Ketogenic Diet.

High amounts of MCTs can cause gastrointestinal disturbances in some individuals, such as vomiting or diarrhea, so the amount of MCTs that can be used depends on each patient’s tolerance. When used, the ketogenic dietitian will usually recommend introducing MCT oil gradually to help ensure tolerance. Like the Classical Ketogenic Diet, the MCTKD is initiated in the hospital under medical supervision and all foods must be weighed using a gram scale.

The MCTKD is frequently used in Europe and Canada. Although the MCTKD is less common in the U.S., MCT oil is often incorporated into the Classical Ketogenic Diet and Modified Atkins Diet. MCT oil may be added to the diet to help boost ketone production or to help maintain ketosis with a lower ketogenic ratio with more protein and carbohydrates allowed.

As always, consult with your health care provider before introducing MCT oil or any other new item into your child’s ketogenic diet.

Do you use MCTs? If so, how do you use them?

-Mallory

 

 

Photo attribution: Flickr user Mattie Hagedorn

Celebrating Halloween on the Ketogenic Diet

Children in halloween costumesHolidays and special occasions often include food and treats. When on a ketogenic diet, it can be tricky to participate in the celebration since foods are limited. For today’s blog post, I compiled some tips and recipe ideas to help you to ensure that your little one has a happy and keto-friendly Halloween.

School Parties:

If your child’s school is celebrating Halloween, be sure to remind your child’s teacher(s) of food restrictions. If there is a class party and candy will be involved, you may want to send some keto-friendly treats (see recipes below) or non-food treats (like Halloween-themed stickers, pencils, temporary tattoos, etc.) for your child to enjoy.

Trick-or-Treating:

As you might expect, commercial candy is off limits for children on the ketogenic diet. Even low sugar or sugar-free candies will contain far too many carbohydrates. However, there is more to trick-or-treating than the candy, so many families allow their child to trick-or-treat without actually eating the candy that they collect. The Epilepsy Foundation recently posted an article about celebrating Halloween on the ketogenic diet and interviewed two keto moms about how they manage. One mom said that her son enjoyed trick-or-treating, then giving away the candy he collected to other trick-or-treaters in the neighborhood. Another mom said that her son likes to bring home the candy he collects to his sister or take it to school to share with his classmates. Another idea is to let your child trade the candy he or she collects for special keto treats, non-food Halloween treats, coins, or even a small toy.

Recipe Ideas for Keto Halloween Treats:

As always, consult with your child’s health care professional to ensure that these recipe ideas are appropriate for your child’s ketogenic ratio and calorie requirements. If needed, your dietitian may be able to help you modify these recipes to reach a different ketogenic ratio.

You can prepare these treats ahead of time, then store them in little Halloween-themed treat bags (for example, these that I found at my local party store) that you can send to school or put in their trick-or-treating bag.

The following recipes are less transportable, but might be a tasty treat to enjoy at home on Halloween.

Read more tips for celebrating Halloween on the ketogenic diet from the Epilepsy Foundation.

How does your family celebrate Halloween on the ketogenic diet? Please share your experiences and tips for other families in the comment section below.

Have a safe and happy Halloween everyone!

-Mallory