In this short educational video, Dr. David Perlmutter addresses the common question of how caffeine affects ketosis. He summarizes a recent Canadian study titled “Caffeine Intake Increases Plasma Ketones: An Acute Metabolic Study in Humans,” published in the Canadian Journal of Physiology and Pharmacology. The study involved ten fasting adults who consumed either no caffeine, a cup‑and‑a‑half of coffee, or three cups of coffee (≈5 mg/kg caffeine). Blood samples over four hours showed that higher caffeine doses produced proportionally higher plasma caffeine levels and, importantly, a dramatic rise in beta‑hydroxybutyrate (a key ketone body). At the highest dose, ketone levels doubled compared to an overnight fast and could supply 5–6 % of the brain’s energy needs. Dr. Perlmutter emphasizes that these effects are observed with unsweetened coffee; added sugars or carbohydrate‑rich meals blunt the ketogenic benefit. He concludes that caffeine, when consumed without added sugars, can be a powerful tool to enhance ketosis.
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Hello everyone, Dr. David Perlmutter here. This is a question we get all the time, and that is, what is the effect of caffeine consumption on ketosis? Everyone's trying to get into ketosis, in other words, burning fat as a primary fuel as opposed to burning sugar. So the question is, what is the effect of consuming caffeine on that whole process? Is it helping or is it hurting? And Canadian researchers have just completed a study where they attempted to answer this question. Let's have a look.
This interesting study is called Caffeine Intake Increases Plasma Ketones: An Acute Metabolic Study in Humans, and it is published just recently in the Canadian Journal of Physiology and Pharmacology. And they explore what caffeine does in the human body, and basically what it does is it promotes what's called lipolysis. Breaking down of fat, increasing FFAs, which are free fatty acids, that then are able to be converted in the liver to ketones. And what the study involved was 10 adults who underwent fasting. They had a breakfast with, I would say, a fairly high carbohydrate breakfast, and then either they had no caffeine, about a cup and a half of coffee, Or 3 cups of coffee, and then they measured their plasma caffeine levels over the next 4 hours and noted, as you would expect, that the highest dosages of caffeine were associated with the highest levels of caffeine in the blood. But they also measured their levels of beta-hydroxybutyrate, one of the so-called bodies— ketone bodies that is often measured, although— Interestingly, beta-hydroxybutyrate is not by definition a ketone, but nonetheless, it's certainly one of the important considerations in the ketogenic diet. And found that at the highest dosage of caffeine, there was really a dramatic increase in the available beta-hydroxybutyrate. And looking at this in a different way graphically, we see again that the 5 milligram per kilogram dosage was associated— and again, that's about 3 cups of coffee— with a pretty robust increase in the level of beta-hydroxybutyrate in the blood. And that this availability of beta-hydroxybutyrate could contribute as much as 5 to 6% of brain energy needs. And, you know, that becomes very relevant when we consider that even a subtle decline in available energy for the brain Could have significant consequences in terms of brain performance. And in addition, they found that the level of ketones that were found in the blood was about twice the level that you would see after an overnight fast. So it really brings us a new appreciation for what our coffee can do for us. But, you know, keep in mind, this is a cup of coffee without the added sugar. Without everything else that people seem to want to put in their coffees these days.
So this is pretty compelling data that demonstrates that in fact caffeine consumption is a pretty powerful way to help get you into ketosis. Keep in mind that drinking caffeine depends on the form. I mean, if you're drinking a cup of coffee with a lot of sugar or having your coffee with a sugar-laden meal, It's not as likely to assist you in getting into ketosis, so keep that in mind. I'm Dr. David Perlmutter. Great talking with you, and see you soon. Thank you.
