Can one cup of coffee help you lose weight and make you smarter?
The cup of java known as Bulletproof Coffee is made from unsalted grass-fed butter with an extract of coconut oil.
The coffee is the brainchild of entrepreneur Dave Asprey. He says one cup will give you up to six hours of sustained energy.
"The No. 1 benefit of Bulletproof Coffee is this mental clarity and lack of cravings that comes because it puts you in a mild fat burning state as if you were on a special diet, even though you're not" he told Inside Edition.
You can make your own at home by pouring freshly brewed coffee into your blender with a tablespoon of brain octane oil — which is derived from coconut oil — and two tablespoons of unsalted grass-fed butter.
Brain octane oil promotes fat burning in the body and gives you extra energy.
One small cup of Bulletproof Coffee has about 200 calories. A similar size cup of black coffee has just four calories.
Doctors cautioned that the high calorie content may be a risk for people with heart disease. The experts say more research is needed before they can recommend it to patients.