Today’s podcast is about Exogenous Ketones – a relatively new supplement. Let’s start with a little bit of background first. If you are in a state of nutritional ketosis the body (the liver) produces ketone bodies, the main ketone body being beta-hydroxybutyrate (BHB).
You can judge whether or not you’re in ketosis by the levels of beta hydroxybutyrate in the blood, so anything 0,5 (mmol/l) and above is nutritional ketosis. (You can also test using urine strips and through the breath but those tests are not as accurate as blood tests which are deemed the ‘gold standard’). With exogenous ketones you’re essentially consuming the same chemical compound but through exogenous form. The idea is that you get the same benefits from a supplement as you do from nutritional ketosis. The benefits include increased energy, appetite suppression and increased mental focus.
Many companies also promote that it is a good way back into ketosis if you slipped out. In the scientific community there are varying opinions on exogenous ketones. Peter Attia believes that they are good for performance but is still on the fence because there is not a lot of proper research on the impact on humans. He has a great podcast with Tim entitled “Drinking Jet Fuel“ which may be of interest. Dom D’Agostino researches exogenous ketones full time, mainly for the effect on military personnel and deep sea divers but he takes the ketones salts himself and he says that he personally notices an increase in energy and focus after taking them even though he is always in nutritional ketosis anyway. Dom was also on Tim Ferriss’ podcast a couple of years ago and mentioned the KetoCana BHB product. Robb Wolf’s personal opinion is that you don’t need them to be in nutritional ketosis and it is really not wise to use them as a tool to try and get back into ketosis after eating carbs. He uses them before intense workouts and notices an increase in performance. Eric Berg is often been quoted as being anti exogenous ketones but if you listen to what he says he is actually against people using these as a tool to get back into ketosis after eating pizza or cake! There seems to be shared opinion that exogenous ketones are not a replacement for a well formulated ketogenic diet but there is a place for them, especially in relation to exercise. Benjamin Bikman warns people against the insulinemic effects of exogenous ketones as they can cause a slight bump in insulin. This may be a concern for anyone eating carbs and using exogenous ketones to get into ketosis. There is not a lot of research on humans but there is a bit more of research on rats. One study that just came out of Canada last year suggested exogenous ketones increased fat oxidation in healthy males during exercise performance but decreased performance, the opposite to what Peter Attia found in a self experiment. Another in humans showed that exogenous ketone supplementation in people on a high carb diet lowered blood glucose and lowered free fatty acids and triglycerides in the blood. The study which showed a decrease in fat oxidation is really interesting but the paper is technical so is hard to interpret – links to all the papers will be posted in the show notes.
We do not recommend taking exogenous ketones if you are not on a well-formulated ketogenic diet. Lee explains that he has taken them when not in nutritional ketosis and didn’t really experience any benefit but when in ketosis (even a mild state of ketosis) the benefits are impressive. Lee often takes them as a nootropic because they really improve mental performance, especially if there is something important going on at work. Lee also uses them to boost performance in the gym and also for appetite suppression. Bronwyn uses them for appetite suppression and if trying to do a longer fast. We have different opinions on the taste. Most are tolerable but some can cause GI disruptions, that said, we’re not taking them for the taste, it’s all about the results. We’ve tested some of the top brands: Perfect Keto, KetoCana, ANS & Kegenix. All have a similar effect by increasing ketone levels by 1,2-1,4 mmol/l but the Real Ketones brand is half as potent which is reflected in the price. The really interesting one is ANS Performance as it has half the BHB as Perfect Keto. The guy who designed it is actually a PhD and he did it because of the high GI impact when using 12g of BHB so he reduced it by half so you don’t get the GI disruption. Weirdly, though, from an efficacy perspective it has the same impact as the others.
The important thing to understand it that exogenous ketones are a supplement; i.e. they are meant to be a supplement to a good quality, healthy diet not a replacement . They can definitely be used to lose weight as they suppress appetite but we really advocate a more holistic approach to your diet. In conclusion, the scientific community is very much in the fence but personally we really like them, especially for the workout, appetite suppressing and nootropic benefits. But it’s important that you make your own mind. It’s up to you, either take them or don’t take them.