What initially sounds like a culinary mistake turns out to be a perfect fit for a ketogenic diet
Coffee can be enjoyed in countless ways: black or with a splash of milk, with or without sugar, sometimes even sweetened with syrup. So why not with a dash of butter? What initially sounds like a culinary oddity has long been known as Bulletproof Coffee— or simply butter coffee—and is anything but new. At its core, it’s coffee blended with unsalted organic butter, ghee (clarified butter), or a small amount of MCT oil (a type of fat composed of medium-length carbon chains) instead of milk.
Fans of Bulletproof Coffee—particularly followers of ketogenic and paleo diets as well as intermittent fasting—credit it with boosting energy and concentration. The high-fat coffee is also said to support weight regulation. The concept traces back to entrepreneur and biohacker Dave Asprey, founder of the so-called Bulletproof Diet, a high-fat take on the ketogenic diet.
Asprey says the idea was inspired by a trip to Tibet, where he encountered traditional tea mixed with yak butter. This beverage has long been consumed there before strenuous high-altitude treks to provide energy and enhance mental clarity. Apparently effective—because the experience ultimately led to the creation of what is now known worldwide as Bulletproof Coffee.
If proponents are to be believed, Bulletproof Coffee comes with several benefits. The main argument: it provides a quick yet steady source of energy without causing blood sugar spikes—unlike carbohydrate-heavy breakfasts. Meals rich in simple sugars often lead to a brief feeling of fullness, followed by fatigue or cravings. Butter coffee, by contrast, is said to deliver longer-lasting energy.
Although far from calorie-free, the drink is almost entirely carbohydrate-free. In theory, this makes it suitable as a breakfast substitute without pushing the body out of ketosis—a metabolic state in which fat, rather than glucose, is used for energy. This, supporters argue, also allows intermittent fasting to continue uninterrupted. For these reasons, many people on ketogenic or low-carb diets consider butter coffee a staple of their daily routine. Reports of improved concentration, mental clarity, and sustained mental performance throughout the morning are common among its advocates.
While butter, ghee, and coconut-derived MCT oil may offer health benefits on their own—thanks to certain vitamins, minerals, and fatty acids—solid scientific evidence specifically supporting Bulletproof Coffee remains limited. Many claimed effects are based largely on personal experience, and reliable studies are still scarce. As a result, findings are mixed.
A 2023 study examining high-fat coffee drinks containing MCT oil and ghee reached a nuanced conclusion. It found no measurable advantage in cognitive performance compared to black coffee. However, participants did report greater satiety, along with a lower expected food intake three hours later—suggesting that while Bulletproof Coffee may not sharpen the mind, it could help keep hunger at bay.
