Can BUTTER coffee give you more energy? The unlikely morning brew that claims to 'shrink waistlines' and 'promote brain function'

By Margot Peppers

Published: 12:25 EDT, 20 June 2013 | Updated: 11:34 EDT, 24 June 2013

A new craze is seeing coffee-drinkers blending their morning brew with up to 80 grams (two-thirds of a stick) of butter, in a bid to boost energy levels and promote weight loss.

Dave Asprey, the creator of Bulletproof Coffee, claims that this concoction is full of healthy fats that will keep your energy levels up 'for six hours if you need it', as well as 'improving cognitive function' and 'shrinking your waistline'.

But some health experts, like Today diet and nutrition editor Madelyn Fernstrom, say the blend - which contains between 100 and 200 calories a cup - can actually promote weight gain, and that any extra energy experienced by drinkers is merely a placebo effect.

The new breakfast smoothie? 'Bulletproof' coffee is an 'energy-boosting' blend of coffee beans and unsalted butter - but some health experts say it may actually promote weight gain, not loss

Mr Asprey says he discovered the power of butter-blended drinks on the top of Mt Kailash in Tibet, at 18,000 feet elevation.

'I staggered into a guest house from the -10 degree weather and was literally rejuvenated by a creamy cup of yak butter tea,' he recalls on his website.

He recreated the energy-boosting effects by mixing unsalted grass-fed butter with his trademark Upgraded Coffee - made from 'low-toxin beans' that make it 'cleaner' than Starbucks coffee.

According to Mr Asprey, butter contains 'all the benefits of healthy milk fat with none of the damaging denatured casein proteins found in cream,' making for 'the creamiest, most satisfying' cup of coffee.

The coffee also contains MCT oil - a blend of coconut and palm oil - which Mr Asprey says is digested faster than other fats and therefore boosts energy and promotes weight loss.

Those who follow a 'paleo' diet, which consists of mainly animal fats and protein, are fans of the coffee since it falls in with their high-fat regimen.

Diet trend: Bulletproof coffee, which also contains MCT oil (a combination of coconut and palm oil) is particularly popular among paleo diet fans, who consume mainly animal fats and protein

Indeed, blogger The Paleo Mama said she tried out the Bulletproof recipe and experienced a satisfying 'high performance buzz'.

Others have pointed out that adding a pat of butter to your morning brew is equivalent to mixing in a few spoonfuls of cream - especially the grass-fed variety, which is reported to have more healthy Omega-3 fatty acids than grain-fed butter.

And while butter and coffee may sound like an unlikely combination, it has actually been consumed around the world for years.

Aside from the Tibetans Mr Asprey encountered, who do indeed drink yak butter and tea at high altitudes, Ethiopians commonly add spiced butter into their coffee.

Origins: Founder Dave Asprey claims he discovered the rejuvenateing power of butter when Tibetans gave him yak butter tea

And in Singapore, coffee beans are often stir-fried with butter in a wok before being consumed.

But as far as health benefits are concerned, some experts disagree with Mr Asprey's findings.

According to Heart.org, butter is very high in saturated fat, an ingredient which raises the level of cholesterol in your blood and therefore increases your risk of heart disease and stroke.

Since Mr Asprey recommends mixing in as much as 80 grams of butter - or two-thirds of a stick - the brew is likely to contain a significant amount of saturated fat.

Other health experts, however, have asserted that saturated fat is actually good for you.

A 2010 study by the Children's Hospital at the Oakland Research Institute in California found that there is no difference in the risk of heart disease between people who consume large or small amounts of saturated fat.

In terms of Bulletproof Coffee's taste, however, when Matt Lauer tried out the concoction on the Today show this morning, he appeared underwhelmed. 'It's terrible,' he said with a look of revulsion.

Still, Mr Asprey and his believers insist that the side effects of drinking butter-infused coffee are solely positive.

'Aside from tasting awesome, it makes you feel lean, focused, and energized,' he promises.

'It allows you to transform your diet without resorting to chewing on sticks of butter (though that's not a bad idea…).'