Bulletproof Coffee: Plenty Of Bull. And Fat Too.

By Angela Dowden — Jun 08, 2019
This concoction is a brew made by smooshing fresh coffee in a blender with grass-fed, unsalted butter and oil. It was invented by Silicon Valley entrepreneur Dave Asprey, who created the recipe after feeling energized from drinking tea with yak butter (seriously) while meditating in Nepal. Is Bulletproof just a bunch of bull? Angela Dowden, an award-winning nutrition and health writer, isn't terribly impressed.
A coffee by any other name would make you less fat. Wellness Mama

When I first heard about “Bulletproof coffee” it was from the perspective of enjoying an eye roll moment at the daftness of some LA diet trends.

I figured that the few folks that managed to down the brew without gagging might find reason to pause once they realized that their coffee had more calories than a McDonald's double cheeseburger.

However, I was wrong to underestimate this fad, and my sentiment has turned from amusement to alarm.

For the uninitiated, Bulletproof coffee is anything up to 480-calories worth of brew made by smooshing fresh coffee in a blender with grass-fed, unsalted butter and medium-chain triglyceride (MCT) oil. It was invented by ex-Silicon Valley techie-turned-entrepreneur Dave Asprey, who created the recipe after feeling energized from drinking tea with yak butter in it while learning to meditate in Nepal.

Bulletproof has now morphed into a multimillion-dollar low carb diet business, with consumption of at least one mug of the buttery oil-slick for breakfast every day as its central doctrine. 

Claims for the drink include that it increases mental focus, banishes hunger and cravings, and triggers weight loss by way of ketosis (the metabolic state triggered by a lack of carbohydrates that means the body burns fat for fuel).

Needless to say, there have been no peer-reviewed studies that show bulletproof coffee has any health benefits at all. But while there are diet fads that simply don’t deliver any benefits, there are others that could actively impact your health for the worse.

Bulletproof coffee is in the latter category, and here’s why:

SO much saturated fat…

For sure, a direct link between saturated fat and heart disease is hard to prove, and saturated fat is not the straight-up dietary villain it was once thought. Nevertheless, there are very good reasons to avoid too much and a Bulletproof coffee made with two tablespoons of butter and two tablespoons of MCT oil can supply 43 grams of saturated fat – over twice the 20 gram recommended daily intake for an adult consuming a 2000 calorie daily diet.

The question is, why would you want to be experimenting with your arteries any way?

The consensus science on dietary fats, which the American Heart Association, the European Society of Cardiology, the UK’s Scientific Advisory Committee for Nutrition and the World Health Organization all agree on, is that to reduce heart disease we should be reducing saturated fats, and more crucially, replacing them with unsaturated fats - the type in nuts, seeds, oily fish and vegetable oils. That means that if you really are set on ruining a good cup of Java by adding fat, it should be olive oil or canola oil, you blend in - not butter, grass-fed or otherwise.


Butter drives up levels of LDL cholesterol and is a complete nonsense thing to be eating lots of, especially in such an unappetizing way. A little butter is fine, but you should be enjoying it spread on some crusty bread, melted over asparagus, unctuous and garlicky inside a chicken Kiev – you get the picture.

MCTs may have some benefits but…

To be fair, some specific saturated fatty acids, may be quite innocuous or even have benefits. This looks to be the case with the two medium-chain triglycerides (MCTs) that make up “Brain Octane Oil” – the preferred MCT oil that Bulletproof want you to use ($48.95 for 32 oz, since you ask). These MCTs, known as capric acid and caprylic acid, have a shorter chemical structure than other fats, and are quickly absorbed and metabolized by the body, which can theoretically promote a feeling of fullness and prevent fat storage.

However, this nascent science on satiety needs to be weighed against the fact that a Bulletproof coffee provides close on a quarter of your daily calories in one measly drink. Fat is the highest calorie nutrient and overall the least satiating. Suffice to say, there are far more nourishing and satisfying ways to spend 480 calories, and you should pick one.

Buttery coffee: it’s just not a great breakfast

Bulletproof coffee for breakfast supplies fat, caffeine, and…nothing else of any nutritional value. 

By comparison, a balanced, filling breakfast such as a couple of poached eggs with wilted spinach on whole grain bread supplies valuable protein, vitamins, iron, and - whisper it - good quality carbohydrate, all for 400 calories. The best bit? You can still get your caffeine boost by having a black coffee on the side.

The “grass-fed” con

Another disingenuous claim in this butter coffee madness is that grass-fed butter is so much better for you than conventional.

It’s simply not.

While it may be true that grass-fed is a bit higher in omega-3s, vitamins A and E, no butter is a very good source of any of them.

The USDA Food Composition Database, says that a tablespoon of butter supplies 97µg (RAE) vitamin A, and a tablespoon of grass-fed butter somewhere around 135µg (I’ve had to estimate the latter figure as the measurement units were different). The important point however is that both of these figures pale into insignificance next to the 1069µg vitamin A that you'll get from a humble cup of chopped carrots.

It’s a similar story with vitamin E  – butter of any type simply isn’t  a great source and you should shoot for  hazelnuts, sunflower oil or sunflower seeds to get a decent amount of this vitamin. As for omega-3s, it’s completely misleading to suggest any type of butter is a good source of these beneficial polyunsaturated fats. Whether grass-fed or not, butter is predominantly saturated fat, and to get a decent amount of omega-3s you’ll need to tuck into some nice oily fish instead.

Be kinder to your guts

On a wider point, drinking Bulletproof coffee often means buying into the low carb, high-fat diet more generally, which apart from being really difficult (as well as antisocial), will also often be low in fiber, with detriment to your gut microbiome and digestive health.

Talking of digestive health, I’ll leave you with this thought - all that fat from a Bulletproof coffee swilled down on an empty stomach can cause really unpleasant diarrhea. 

So put down the Bulletproof coffee right now and just enjoy a normal cup of Joe with your healthy breakfast - you know it makes sense.