Coffee with a dash of... butter? According to creator and founder of Bulletproof Coffee, David Asprey, the latest trend claims to boost energy levels, improve cognitive function, and shrink your waistline.

But you may not want to swap the low-fat milk for butter just yet.

According to Asprey, he discovered the power of butter-blended brews atop Mount Kailash in Tibet, at 18,000 feet elevation, rejuvenating himself with a creamy cup of yak butter tea, he notes on his website.

Asprey's attempt to recreate the energy-boosting effects involves an unlikely brew. A mixture of unsalted grass-fed butter with his trademark Bulletproof Upgraded Coffee — a blend of low-toxin beans, which his site claims to be "cleaner" than Starbucks coffee. Grass-fed butter, according to Asprey, boosts health benefits, "optimizing" your cholesterol levels instead of worsening them. On his website, he claims that starting your day with the Bulletproof-Butter brew will "give you lots of energy and it will give your body healthy fats that it will use to make cell walls and hormones."

Additionally, Asprey praises the "boundless energy" and "focus" you will feel following a cup. And only that. In addition to butter coffee, Asprey recommends eating nothing for breakfast. According to him, skipping breakfast is crucial to boosting energy levels and cognitive function.

But several experts don't think this is a good idea. Diet editor Madelyn Fernstrom, Ph.D, for one, says that the butter-coffee combo creates a 100-200 calorie cup of Joe and can actually promote weight gain.

Asprey's recommendation involves adding as much as 80 grams of butter — or two-thirds of a stick — which adds a significant amount of saturated fat to the coffee.

While the Tibetans have drunk a butter-tea concoction for centuries, the beverage is more to ward off the cold climate and provide a rich drink that will sustain energy levels in the intensive work environment. However, before beginning a typical day at the office, seated at your desk, a hearty 200-calorie cup of butter-coffee might actually have harmful health effects.

The American Heart Association (AHA) provides a different view on consuming foods high in saturated fats, butter being among them. Saturated fats raise your level of cholesterol in the blood, increasing your risk for heart disease and stroke.

Asprey claims that drinking butter coffee will amp up energy levels, and "if taken before a workout, could improve your performance and give you an edge." More likely, the butter coffee removes bitterness of the beans and offers a creamy alternative. But if you're looking to improve heart health or lose weight, butter coffee may not be the right brew for you.