The brainchild of Dave Asprey, bulletproof coffee is a trend that hit the diet world in 2014. It has been hailed as the ideal energy booster - especially for those on the keto diet, or those on other restrictive diets, like the low-carb or Paleo diets.
But what is it? And is it good for us? In this article, I explore why the drink has such specific ingredients, and why - although not harmful to our health - it's not quite the miracle drink people hope for.
A cup of bulletproof coffee has a list of very specific ingredients. According to the official Bulletproof website, the recipe is:
First of all, it's not everyday you use the phrase â€˜MCT oil' - so what is it? Medium chain triglycerides (MCTs) aren't found in most foods. Usually, what we eat contains long-chain triglycerides. MCTs are broken down quicker by the body and head straight to the liver.
The liver then gets to work, converting these fats efficiently into energy, rather than storing them as fat within the body. MCTs are typically found in dairy products, coconut oil and palm kernel oil.
Secondly, the founder of bulletproof coffee stresses the importance of using butter made from grass-fed cows. This is because they are believed to be healthier than grain-fed cows.
The combination of the above doesn't sounds like the most appealing mix, so why drink it? And should you?
Most people who convert to a cup of the coffee, butter and MCT oil mixture every morning have the same goal: weight loss.
Bulletproof coffee is all too often used as a meal replacement - so the combination of fat-burning MCTs and a reduced calorie intake may lead to some initial fat loss. In those following the keto diet, the energy gained from a fat-based diet will lead to this type of coffee helping them to feel full too, stopping them from snacking throughout the morning.
However, long-term, high fat intake (and needing to reintroduce carbs to a diet, if you're a ketogenic dieter) may have the reverse effect. What's more, for non-keto dieters, a high-carb AND high-fat diet can also lead to weight gain.
It should also be noted that fat contains more calories per gram than carbs. So overindulging might leave you with a calorie surplus (where you're eating more than you're burning off) which will also lead to weight gain.
Bulletproof fans often claim that the drink boosts their cognitive function. This improved mental clarity is said to help them to focus and work harder. But really, this is likely down to the regular caffeine and fat intake - both of which can be sourced from elsewhere in a healthy diet.
Again, those following the keto diet may actually feel as though this is a health benefit, though. Because they are getting their energy - and therefore their brain's energy - from glucose (via carbohydrates), they require ketones (via MCTs). Bulletproof coffee will provide them with ketones - but again, so will many other aspects of their diet.
As a low-carb breakfast replacement (allowing for easier control of blood glucose levels), the energy gained from fat with this drink seems like it'd be a smart choice for diabetics.
However, when take into account other factors like potential weight gain and a lack of nutrients, whilst a cup of this coffee wouldn't cause any harm if consumed every now and then, a diet focused on healthy foods would be more beneficial.
The idea that the drink should replace breakfast means that people often miss out on some valuable nutrients. Bulletproof coffee offers little in the form of nutrition - mainly consisting of saturated fat, and no fiber, carbs and little protein. A well-balanced diet would contain all of these nutrients.
But it's not the coffee itself that's the problem - coffee actually has a whole load of health benefits that can help you be healthier, and even live longer.
However, when it comes to saturated fat - whilst it isn't as bad for our health as we first thought - too much isn't going to be good for us in the long run. And if you're already at-risk of cardiovascular disease, adding unnecessary saturated fat do your diet may further increase your risk of developing a heart-related condition.
Overall, adding bulletproof coffee to your diet is probably only going to benefit you if you are on the ketogenic diet (which I don't recommend, either). For everyone else, replacing your breakfast with it can add empty calories and a lot of fat to an otherwise well-balanced diet.