London – With the array of macchiatos, lattes, cappuccinos, Americanos and mochas already on offer at coffee chains – not to mention all the milks, shots and syrups you can add to them – you might have thought that every coffee craving was already covered.
But a new caffeine craze – ‘butter coffee’ – is sweeping cafes, and it’s arguably the weirdest yet.
A double espresso blended to a thick froth with a tablespoon each of butter and coconut oil. It sounds like a heart attack in a cardboard cup, but the new research finding that fat is better for us than sugar means it is becoming popular with the body-conscious.
What started as a diet fad in America is rapidly gaining ground in the UK.
Variously labelled ‘bullet coffee’ or ‘fat black’, a cup can be had at branches of trendy foodie store Planet Organic in London, or at outlets of juice chain Crussh, where it’s called ‘Smart Coffee’. It’s also easy to make at home, with many recipes on the internet.
Fans are even drinking it as a meal substitute. They claim the combination of ingredients makes it the perfect breakfast-in-a-cup, giving you a prolonged energy hit, which sharpens your focus, burns calories, strips you of excess body fat and leaves you feeling full until lunchtime.
The downside is that the cloying texture makes it an acquired taste and those trying it for the first time often complain of nausea and diarrhoea.
The oily brew is the brainchild of US entrepreneur Dave Asprey, who was served tea laced with yak butter when trekking in Tibet and became intrigued that mountain climbers use the drink for energy and sustained concentration.
He went on to devise what he calls ‘the bullet-proof diet’ – a high-fat, low-carbohydrate regimen which, he claims, protects against fatigue, flab and chronic diseases, as well as promising dramatic weight loss.
The theory is that if you’re not filling your diet with carbohydrates (such as sugar, bread and pasta), your body will use fat as fuel instead.
This is called ‘ketosis’. The ketogenic process is what makes Atkins and other low-carbohydrate diets work, but it is frowned upon by conventional weight-loss experts, who say that low-carbohydrate diets can lead to headaches, muscle cramps, general weakness and digestive problems.
Butter coffee is central to the success of Asprey’s diet and he says the blend should combine organic coffee (he claims it’s toxins in ordinary coffee that give you the jitters) with grass-fed, unsalted butter (milk from grass-fed cows purportedly has health qualities superior to those of milk from grain-fed cows), and organic coconut oil.
The result is a thick, creamy coffee with a distinctly fatty, coconut aftertaste. And according to Planet Organic, which has been selling it for more than a year, its popularity is steadily growing.
Its greatest appeal is as a breakfast drink among fans of extreme exercise (such as ‘Cross Fit’, an intense regime that involves lifting heavy weights) because of its claim to boost stamina and performance without dulling muscle definition, and the Paleo diet, which advocates a return to the unadulterated hunter-gatherer diet of our distant ancestors – no sugar, grain, junk or processed food.
Nutritionist Suzie Walker, 33, is a convert. ‘I like to start the day with a bullet coffee,’ she says. ‘It fills me up, keeps me focused and I don’t have to think about eating again until lunchtime.’
Like many butter coffee converts, Suzie blends her own cup every morning. ‘You get a really good frothy head if you mix it in a blender,’ she says. ‘It’s lovely!’
Complete beginners can buy a bullet coffee starter kit containing coffee beans, butter and oil from Amazon, though it might be wise to taste one first.
Suzie has been a devotee of the Paleo diet for more than a year, and recommends it to her weight-loss clients.
‘I adopted a Paleo approach when I finished breastfeeding my daughter Grace, who is now three, lost a stone (about 6kg) in weight and never felt healthier,’ she says.
She lives in Cookham, Berkshire, with her husband Stuart, who shares her dietary persuasions (they eat cauliflower instead of rice or potatoes). She discovered butter coffee online and says she enjoyed it from her first cup.
Asprey’s health claims for the coffee are certainly persuasive. The double shot of caffeine will speed your metabolism (studies have shown this) but the addition of fat (in the butter and coconut oil) slows the digestive process, preventing a sudden energy spike, which means the coffee ‘hit’ is gentler and lasts longer than it normally would.
Grass-fed butter is also supposedly rich in cancer-fighting antioxidants, good cholesterol and vitamin K2 (which plays a role in ‘decalcifying arteries’) as well as omega-3s, fatty acids and betacarotenes, all of which are good for the brain, stamina and immune system.
Adding coconut oil gives a boost of lauric acid (a fatty acid), which some believe to be good for the immune system, and a particular type of fat called ‘medium chain triglycerides’ (MCTs). It has been argued that these MCTs are metabolised directly in the liver, meaning that they are more likely to be burnt as fuel than stored as body fat.
However, one cup of butter coffee packs 400-500 calories - more than a bacon sandwich - and 50g of saturated fat, which brings you close to your total daily allowance of 70g in just your first drink of the day.
As a result, many experts say it is hard to understand how this can possibly contribute to weight loss. Dietitian Dr Sarah Schenker says: ‘Ketosis is only triggered when the liver glycogen stores are depleted, so if you enjoyed a carb-heavy takeaway the night before, your morning cup of bullet coffee won’t be enough to make the switch.’
By the same token, if you succumb to a baked potato at lunchtime or a couple of biscuits mid-afternoon, the low-carb magic will be lost and your butter coffee becomes no more healthy than buttered toast.
Although butter is very high in saturated fat, studies increasingly suggest that the link with heart disease is contentious. But there are concerns that too much butter (and some bullet coffee blends contain two tablespoons of the stuff) could increase cholesterol levels, raising your risk of heart disease.
Certainly, by drinking a high-fat, high-calorie drink for breakfast without making other changes to your diet or lifestyle, you are more likely to gain weight than lose it.
‘If you are trekking in Tibet you need concentrated calories because you are expending so much energy,’ says Dr Schenker, ‘But you can’t just transfer the drink to our more static Western environment and expect it to aid weight loss: it just won’t work.’
She suggests sticking to regular coffee without cream, butter or sugar - however rare it might be nowadays to ask for a simple, straightforward coffee with milk.