I honestly thought that exogenous ketone supplements were a thing that people had already decided was – in most cases – a bad idea. I was wrong. When I joined the group I’ve mentioned recently on Facebook, the posts and comments from people slammed me in the face. Let’s talk about them, shall we?
So, what are ExoKs? They are ketone esters or ketone salts – in a liquid or pill form. Typically they will include stuff like powdered MCT oil, sodium, and sometimes minerals and electrolytes like potassium or magnesium. In the case of the brand Pruvit, they contain a high dose of caffeine. This can be problematic. There’s three components or ketones used by the body – acetoacetate and beta-hydroxybutyrate. Acetone is a third, less abundant, ketone body. ExoKs only contain beta-hydroxybutyrate. The claims made by the manufacturers of these supplements say they put you into ketosis faster, keep you in ketosis, shed the pounds off you, reduce appetite, and are completely safe. Let’s break these (unsupported by peer-reviewed studies) individually, ok?
Will put you in ketosis faster:
Faster than what? About an hour before you wake up, even if you ate 100g of carbs the night before, you are in ketosis. The key to a ketogenic diet is sustaining ketosis. You do that by keeping your carbs low throughout the day. So, faster than diet? I’d call that a draw.
How do they define ketosis?:
They use the most basic definition of ketosis – presence of ketones in the blood and urine. On this value, yes, they put you in ketosis. But, it’s not that simple. Actual ketosis is the metabolic process of creating ketones by the liver from fatty acids and amino acids. The liver does this from either body fat (desired) or dietary fat (still not a bad thing). The liver knows that too many ketones in your system isn’t good (I’ll get to that in a minute), so in the presence of ExoKs, it doesn’t produce ketones. From a practical perspective, they do not put you into actual metabolic ketosis.
Keep you in ketosis:
Again, if we are talking just the presence of ketones in the blood, then taking these supplements every 4 hours will maintain blood and urine ketone levels. If we are talking actual metabolic ketosis, then no. They don’t. They do the opposite. They stop metabolic ketosis.
Shed the pounds off you:
This is a grey area. A few small studies have shown an insignificant – but present – lose of body weight using ExoKs. Unfortunately, there’s no data if this weight lost was from lean mass, brown fat, or fluid loss. I’ll call this a toss-up. On the other hand, a well-planned and executed metabolic ketosis lifestyle most definitely can shed pounds. Here’s the thing, though, the minor weight loss seen in some subjects is considerable less than you can achieve with keto. Why? Metabolic ketosis burns body fat. Supplemental ketosis does not. I can’t make it any simpler than that. If you are taking ketones, you aren’t making them. Making ketones is what takes off body fat.
They get the nod on this one. Studies have shown that ExoKs, when taking by normal weight individuals after a fast did reduce appetite, as well as lower insulin (not always a good thing), lower ghrelin (a good thing), and higher leptin. Unfortunately, this only appears to work with fasted individuals. Studies done with people eating a normal feeding schedule showed no difference. They do contain about 100kcal of nutrition, so that needs to be added to your macro calculations.
They are completely safe:
If the individual is already ketogenic, taking only the recommended dosage, has no history of diabetes or cardiac health concerns, then probably this answer is yes. Otherwise, there’s a few issues we need to discuss. 1) In the case of Pruvit, as mentioned above, it contains a high dose of caffeine. This can be helpful for energy, but dangerous if you have a variety of medical conditions. High levels of caffeine can cause seizures, hypertension, convulsions, chest pain, irregular heartbeat, insomnia, hallucinations, and confusion. Not sure – even as a Hobbit – that I’d risk that. If you are taking them and eating a normal (non-ketogenic diet level) of carbs, since it suppresses insulin levels, there is the risk of ketoacidosis, which can be fatal.
Is there any time that these are good?
Depending on the formula, yes, actually, there are times when they might be beneficial: A recent study shows a reduction of symptoms for Alzheimer’s. An animal study – not human – on animals having a regular (non-ketogenic) diet had reduced seizures and anxiety in rats. Studies done by the US military showed that in high-stress, sleep-deprivation, extreme high-intensity activity did show an increase in performance, both physically and mentally. In high performance athletes, it showed a conservation of muscle glycogen in competitive, long-range cyclists.
They are expensive. They can be dangerous. They don’t do nearly as much as they advertise. They have a very dodgy business model (most are MLM). They don’t do anything you can’t do naturally, and don’t do the one thing you CAN do naturally with a well-formed keto diet: burn body fat.
Here’s a few links to read on the subject from people I consider respectable, intelligent, and steady: