Keto 101

Keto 101

There have been many (perhaps too many?) blog posts, articles and books written in the last few years about the ketogenic diet and nutritional ketosis. I myself have been guilty of jumping on this train both in my own personal diet practices, blog posts, and podcast interviews. Although we’ve talked extensively on this website about low carb/high fat diet and fasting we haven’t done much formally about the ketogenic diet/ketosis, aka Keto. With that said, let’s dive into part one of all things Keto!

What are ketones?

First let’s start off with some basic definitions. What are ketones? They are chemical substances produced naturally by the body.  For more than you ever wanted to know, click here of just keep reading this post!  The 3 “ketone bodies” are:

Acetoacetate

Beta-hydroxybutyrate

Acetone

What is Ketosis?

Now that your an expert in biochemistry, lets move on to more important topics that you actually care about.  For starters: what is ketosis? Contrary to what you may have heard or read on Facebook, ketosis is not some magical trance-like state of fat loss, it is simply the physiologic state where ketones are circulating in the bloodstream.  Practically speaking, this begins when a significant concentration of ketones become detectable in the blood or urine, which is typically around a level of 0.5 or 1 mM (pronounced mili-molar, a unit of measurement).  Most folks are more used to the mg/dL units commonly seen on blood tests; to convert mM to mg/dL just multiply by 18.

What about ketoacidosis?

As I discussed on my recent podcast interview, ketosis is NOT the same thing as ketoacidosis, a very dangerous metabolic condition. Unless you are a Type 1 diabetic, the chances of experiencing ketoacidosis is very low (but not impossible).  This is because Type 1 diabetics have a compete  (or near complete) lack of insulin due to autoimmune destruction of pancreatic islet cells where it is produced.  If these individuals develop very HIGH blood glucose levels without the counter-regulatory effect of insulin, subsequent physiologic adaptations and perturbations lead to acidosis and ketosis—and if left untreated—death.  The good news for non-diabetic individuals with a functioning pancreas is that it’s almost impossible to have high blood sugar and ketosis simultaneously.

What are the role of ketones?

You may have heard it said that the body needs glucose/sugar to function. While this is technically true, there is a subtle distinction between your body needing glucose and you needing to eat it.  This is because the body can create its own glucose out of protein via a process called gluconeogenesis.  Likewise, many tissues in the body do not need glucose at all and can function just fine by metabolizing fatty acids and ketone bodies for energy. The brain in particular seems to thrive on ketones. And from an evolutionary perspective, this makes a lot of sense. Think about our early human ancestors roaming the plains of Africa, or the cave man in northern France, or a modern day Inuit.  In the natural world without 24 hour drive-thru’s and refrigerators there were times of food scarcity. If the body became weak and the mind scattered and distracted it would have of spelled doom for humankind, as we would become susceptible to predation and less likely to succeed in our efforts to hunt or forage for nutritive food. In this way, ketones literally are an evolutionary mechanism that allowed us to not just survive–but thrive–in times of scarcity.

How do I achieve ketosis?

There are three main ways to achieve ketosis.

1. Fasting. After approximately 24-36 hours of fasting, the body’s natural reaction is to start making ketones for fuel.  As discussed above, this is our homeostatic response to dietary scarcity. The longer you fast the higher your ketones will get. After about 3-5 days of fasting ketones reach the range of 3 to 7 mM. At the high-end of that range I would start to worry more about ketoacidosis, however I still think it’s exceptionally rare. It’s important to note that individuals vary with respect to how quickly and deeply they get into ketosis.  This has a lot to do with how the body metabolizes fat, liver health, and probably many other factors.  For instance, Rachel can get into a pretty deep level of ketosis in less than 24 hrs, while it takes me much longer.  It’s also worth mentioning briefly here (although we will get into more detail in a later post) that the level of ketosis doesn’t mean too much.  Most advocates of the ketogenic diet and fasting/nutritional ketosis recommend that you don’t even check your ketone levels, and if you do check, to do so infrequently.
2. Ketogenic diet. This is a day that is very high in fat, quite low in protein, and very low in carbohydrates.  The typical macronutrient breakdown would be something on the order of 75% fat, 15-20% protein, and 5-10% carbs. Again, individuals will vary; some people will be able to incorporate more protein or carbohydrates without coming out of ketosis. As mentioned above, for most applications, there is probably no need to hit a certain level of ketonemia to achieve the benefits.  But for others, such as controlling epileptic seizures in children, the level of ketosis may be more important.
3. Exogenous ketones. These are lab created ketone products that you ingest, and there are two varieties currently available.  The first are the ketone salts and I have personally experimented with these.  I have used it a handful of times in different settings, from fasting, to pre-workout, to just a regular day at the office.  In terms of getting into ketosis, they do work: I have tested my blood before and after ingesting them, and have seen a small rise in measurable ketone levels.  But otherwise I haven’t been too impressed.  I didn’t feel particularly great and the ketosis didn’t last long (since the body isn’t actually making them, they get burned up pretty quick).  The second option are ketone esters. These are new to the market and I haven’t personally tried them yet. They work quicker, achieve a higher level of ketosis, and are more expensive. These are currently available for sale and are being tried by elite athletes and military applications.  All exogenous ketone products are naturally foul tasting and are often combined with exceptionally sweet additive such a Stevia to make it more palatable. Personally I find this even less palatable as my body is not adapted to the super sweet taste of the supplements.

In part 2 of this series we will take a deeper look at why so many people want to experiment with ketosis.  We’ll look at the benefits of ketosis, from weight loss, to metabolic health, to prevention of chronic disease.  If you leave a question in the comments section below, I will try to incorporate your questions into the next post.

~Brendan