What’s the deal with Exogenous keytones and how to use them

Going “Keto” can be hard, really hard. There are many health benefits to the ketogenic diet, but transitioning from carb sources to fat sources as your primary source of fuel (aka “ketosis) can be rough. The transition can even leave you feeling like you have strange symptoms that feel more like the flu. These feelings are known as the “keto flu”.  It’s a very undesirable way to feel – irritable, lethargic, headachy and/or bloated – and it’s how you might feel until your body adjusts to the diet changes. You may have already experienced a similar reaction – just take carbs out of your diet for a day and you may notice that feeling begin to creep in.

Why does this happen?  As your body is transitioning from using carbohydrates to using fats as its primary fuel source, there is an “in between” phase.  The body isn’t quite efficient at burning the new fuel source (ketones) yet, and therefore you feel the symptoms associated with an inadequate energy supply. Is there anyway to mitigate this reaction? Fortunately, yes. Quite popular right now amongst the keto crowd are “exogenous ketones” — external ketone sources that help you have adequate energy supply while you are going through the “in between” transitioning phase. And there are several other benefits associated with using these exogenous ketones including fat burning and enhanced energy.  But before I make exogenous ketones seem like a miracle supplement, let me explain what exogenous ketones are and how to use them safely.

Exogenous ketone sources
The word “exogenous” simply means coming from outside your body. Whenever you take something from an external environment to your internal one, you are taking an “exogenous” source. Exogenous ketones are supplements we can take that help mimic being in a state of ketosis. There are three main types of exogenous ketones to be aware of:

  1. Ketone esters
    These are ketones in an unbound state. They are molecular compounds not attached to any other compounds, which means they can be used a little more readily and quickly compared to molecules already bound to something else. These are, in theory, the supplements that help you raise your blood ketone levels faster. Higher blood ketone levels mean fewer “keto flu” symptoms.  Sounds like a win/win right? Well, the downside to taking these is that you trade your “keto flu” for a nasty tasting supplement that often causes gastric distress, based on reports from many consumers. More like a win/what-else-is-out-there?
  2. Ketone salts
    These ketone molecules are typically bound to some other molecule, usually a mineral. Calcium, magnesium and sodium are the more common minerals these are bound to. In this bound state, the ketones won’t be used as quickly as the unbound ketones, but you will be able to enjoy the taste better. Blood ketone levels will rise, just not as rapidly. They also seem to have limited gastric distress symptoms involved.
  3. MCT oils
    These are not ketones themselves but offer an indirect source of ketones. MCT oils are fats that are shuttled into cells for use for energy. The by-products of these specific fats being shuttled into cells and used are ketone bodies; therefore, these oils work in an indirect way as opposed to being a direct source of ketones. They don’t tend to have an impact on raising actual blood ketone levels and can be higher in calories, so, depending on your goals, these might not be as ideal as using direct ketone sources.  But these offer a different option to the direct ketone sources if they are not what you are looking for.

What can I use exogenous ketones for?
Exogenous ketones can be used for several purposes, namely reducing the symptoms of transitioning to ketosis, fat burning, energy / athletic performance and/or mental performance.  We’ve already mentioned using ketones to help eliminate “keto flu” symptoms, so let’s move on to fat burning.

  1. Fat Burning: The premise behind the ketogenic diet is that it uses the fat stored in your body as its primary fuel source; therefore, in theory, the faster you can get into ketosis and stay there, the more fat you will be able to burn. Exogenous ketones can help you transition into ketosis faster than you could without using these supplements. With the proper dietary changes and commitment to a ketogenic diet, these supplements can help you reach a fat burning state much faster.
  2. Energy / Athletic Performance: Workout energy, at the start, comes from glycogen (carbohydrate energy). However, if you are a high performance athlete, your body can quickly burn through your glycogen stores and start searching out fat sources for energy.  You will undoubtedly experience a dip in energy during that transition which is not ideal especially if you are in the middle of a marathon, triathlon, or competition etc. Exogenous ketones can offer you an extra boost of energy during that transition period. They can also help you use oxygen more efficiently during your workout, which could be a whole blog post on its own to explain.
  3. Mental Performance: The brain needs a lot of energy to work. In short, ketones can cross the blood brain barrier directly and offer energy for the brain to use. Carbohydrate sources need to be further processed before they can get past that blood brain barrier and to your brain as fuel. If you feel “brain fog” on a regular basis, like I said in my last blog post (Part 1), trying a keto diet might be for you.  You might finally get the proper energy source to your brain that it has been looking for.  Exogenous ketones can help you get there faster and supply your brain efficiently during the transition period from the standard American diet to keto.
  4. Coming back to keto: What if I start but then fail at keto and want to come back?  Sometimes you can be following a ketogenic diet and “fall off the wagon” for a few days, eating higher than permitted carbohydrate numbers. Or perhaps your high performance as an athlete mandates a higher carbohydrate intake for a few days. In that case, exogenous ketones can help you get back to dietary ketosis with fewer side effects of the transition phase. Here you can use them to get you back to nutritional ketosis faster.

Exogenous ketones sound great, right!? You might be wondering if you can just add them to your daily regimen now without any nutritional change and still reap the benefits. But unfortunately no, the health benefits documented above were all associated with exogenous ketones taken in conjunction with nutritional ketosis. It is not advised to use this type of supplement apart from dedicating to a dietary change as it’s not recommended to expect health benefits from supplements alone if you’re not willing to eat clean whole foods and especially high amounts of organic fruits and vegetables. If you’re interested in exogenous ketones for the benefits, but still want to enjoy high carbohydrate intake in your diet, then this supplement is not for you. The fat-burning impact of exogenous ketones is appealing to many people, and undeniably so. Just look at how much money the weight loss industry brings in every year while people search for fat-burning miracles on the market! Exogenous ketones are not a magic weight loss pill – they must be used safely and supported nutritionally.

Safety concerns
It’s always important to speak with your medical professional before introducing any new supplements to your daily regimen. Each individual body has unique needs, and speaking with your primary care provider, especially one that has extensive knowledge of supplements and their clinical research, is always advised.

One thing to be aware of when considering taking exogenous ketones is that exogenous ketones have been shown to reduce blood sugar levels significantly in a few recent studies [1]. If you have lower glucose levels to begin with, this supplement may not be the best fit for you.

To recap, the best and most well documented uses for exogenous ketones are:

  • To help transition you into nutritional ketosis without having to experience the negative side effects (the “keto flu”)
  • The enhance energy levels in higher performance athletes
  • Assistance remaining in ketosis if you “fall off the wagon” for a day or so and need to stay in ketosis

We don’t have a lot of longterm research with respect to exogenous ketones just yet since they are relatively new to the market.  Always keep things like that in mind when exploring new supplement options.  But I think these are definitely worth a try given the positive response from consumers. Exogenous ketones are a safe way to help you reach your nutritional ketosis goals.

Perfect Keto Exogenous Ketones available in Canada, as they are one of the best exogenous ketone brands on the market. They have been formulated by a doctor, are extremely effective, and taste much better than standard exogenous ketones.

You can view the Perfect Keto collection of products here.

In health,

Dr. Tara

1. Effects of exogenous ketone supplementation on blood ketone, glucose, triglyceride, and lipoprotein levels in Sprague–Dawley rats; Nutr Metab (Lond). 2016; 13: 9.

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