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Bulletproof coffee, also known as butter coffee, is a high calorie drink made with added fats, intended to fuel your start to the day. It was created by the originator of the Bulletproof Diet, Dave Asprey, an American entrepreneur and author. The drink has become popular with low carb dieters and followers of ketogenic eating plans. Read on to discover the research behind the health claims, who shouldn't be drinking it, and how to make bulletproof coffee at home.

Discover our full range of health benefit guides and also check out some of our coffee recipes, including delicious drinks and bakes.

How to make bulletproof coffee

Bulletproof coffee combines coffee, made from high quality beans, with unsalted butter and a medium chain triglyceride (MCT), such as that derived from coconut oil. The ingredients are blended together, served warm and resemble a creamy latte.

When do you drink bulletproof coffee?

Many high-carb, heavily processed breakfast options such as cereals, toast or pastries provide a quick energy boost, but may disrupt blood sugar and leave us craving another sweet fix. Dave Asprey argues that bulletproof coffee provides the fuel to start your day, whilst offering a low-carb alternative to carb-laden breakfasts.

What are the potential benefits of bulletproof coffee?

Although there's been plenty of research into coffee consumption in general, there have been few studies specifically looking at the effects of bulletproof coffee, so more research is needed before we can draw any firm conclusions.

Bulletproof coffee is claimed to help you feel satiated, alert and focused. Although, there have currently been no specific studies relating to bulletproof coffee, it's well documented that drinking coffee in the morning may help you feel more awake and alert, improve short term recall and reaction time, thus improving performance, with effects potentially lasting a few hours.

Research also suggests that normal caffeine intake has an effect on increasing resting metabolic rate and thermogenesis (our bodies' process of producing heat).

Key componenets of bulletproof coffee include fats from butter and MCT oil. It's claimed this will quash appetite, stabilise hunger and provide calories to fuel your morning. As well as being calorie-rich, butter supplies fat soluble vitamins including A, D and K, is a source of gut-friendly butyrate and supplies conjugated fats, which may help improve body fat composition.

For those following a low-carb, high-fat diet, bulletproof coffee fits the ketogenic style of eating because it contains no carbs and the body converts the MCT oil to ketones. This effect is thought to be more effective in the absence of a meal.

MCT oil is metabolised by the liver and absorbed quickly by the body, thus supplying a ready source of energy. This makes it potentially useful for those seeking weight loss, although more studies are needed to validate these findings.

Recent studies examining low-carb, high-fat diets appear to suggest that on average, such diets don't necessarily increase your levels of total and LDL cholesterol. However, it should be emphasised that the effects on long-term health are unknown and recommendations for daily fat intake remain unchanged. Based on the available research, ketogenic diets may be associated with some improvements in cardiovascular factors including obesity, type 2 diabetes and HDL cholesterol levels, however, these effects are thought to be limited over time.

What are the potential downsides of bulletproof coffee?

One of the main downsides of drinking a bulletproof coffee instead of breakfast is that you're missing out on the opportunity to eat a nutrient-dense meal. Instead, you're consuming a drink that's high in fat, but lacks other valuable nutrients.

The fats included in bulletproof coffee are predominantly high in saturates – for example, just 1 tbsp of unsalted butter supplies 12.3g fat, more than half of which are saturates. When combined with the recommended MCT oil, one cup of bulletproof coffee will supply more than your maximum daily reference intake for saturated fat (20g) and approximately 242 - 354kcal per cup (depending on the amount of butter added).

It’s well known that caffeine gives us a boost, and it does this by acting as a trigger on our adrenal glands, the organs which manage our stress response. High intakes of caffeine over an extended period of time may tire the adrenal glands, which will impact our endocrine system and subsequent hormonal balance. Also, some people find that consuming caffeine activates the stress response, and may increase the body’s reaction to perceived stress during normal daily activities, such as in a work environment. Some animal studies have also suggested that the effect of caffeine on our adrenals may be particularly relevant at certain life-stages, such as during puberty.

Many of us consume caffeinated drinks for these stimulatory effects. Bulletproof coffee is typically consumed first thing in the morning, however, some experts argue that it may be better to wait until around 10am to drink your first coffee of the day. This is because your natural cortisol levels generally peak between 8-9am, so the effect of caffeine may be more effective when they start to dip later in the morning.

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For some people, who are sensitive to the effects of caffeine, regular consumption may increase anxiety, headaches and cause sleep disturbance.

Furthermore, studies do not support the effect caffeine has, by itself, on appetite suppression.

Is bulletproof coffee good for you?

Although claims suggest that bulletproof coffee may prevent hunger, support energy and be a weight loss alternative to breakfast, there is not enough evidence to confirm this. Moderate coffee drinking may have health benefits, although adding large amounts of saturated fat to your coffee may not be good for the longer-term health of some people. As a meal replacement, bulletproof coffee makes a poor nutritional alternative to a balanced breakfast.

If you're considering incorporating bulletproof coffee into your diet, it's worth checking that your blood fats (including cholesterol) are not elevated. The current advice for those with cholesterol problems is to avoid an excessive intake of saturated fats, including butter. Speak to your doctor if you're concerned that your dietary choices may have an impact on your risk of heart disease.

Pregnant women are advised to minimise their consumption of caffeine and to eat regular balanced meals, so bulletproof coffee is unlikely to be appropriate.

Now read

Is coffee good for you?
The health benefits of coconut oil
What are the health benefits of drinking water?
Best coffee machines

This page was published on 2nd March 2020.

Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a postgraduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.


All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.

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