'Bulletproof" coffee has been something that has saved my butt time and time again. It's something that I've come to rely on sometimes.
So, first, let me say that I've been a big coffee drinker since I was young. Caffeinated or not, I love almost all warm beverages. All kinds of coffee, teas, and even hot chocolate all are delicious to me.
Also, being a professional fighter, I need to maintain a certain weight and come to a weigh in exactly on weight or I don't get paid. It's part of my job. The way you lose weight is by burning more calories than you take in. It's a numbers game. That's all. That doesn't mean that the 'what kind' of calories you're eating doesn't translate to 'what kind' of weight you are losing and what your body is composed of. "Bulletproof" coffee just is a way to keep yourself energetic while on a fast, which will help you maintain a caloric deficiency in order to lose weight.
Now, the term "bulletproof" coffee was coined by the guy at bulletproofexec.com when he designed the idea of "bulletproof" coffee for westerners. He claimed came up with the idea while climbing in the Himalayas and drinking some kind of tea with yak's milk. He saw the benefits of it and wanted to make an accessible version for westerners. He designed making coffee, then mixing grass-fed unsalted butter and MCT oil and blending it up.
He's made a business out of selling the supplies for it. He sells coffee and MCT oils for making "bulletproof" coffee. He goes into telling everyone why his coffee and his oil is the best. Personally, I think he says all that stuff mostly to make money. I mean, that makes sense. But, personally, I think that its not necessary to spend a ton of money on coffee, though I think that a little more expensive company can be way more delicious. Secondly, I don't think that MCT oil is necessary, but that coconut oil works just as well. If you like the taste of the coconut oil, I say just use that. Grass-fed unsalted butter isn't super expensive, so I usually get Kerrigold Irish butter at Trader Joe's for like $6 and it does the trick.
Here's the formula I use. I grind my own dark roast Trader Joe's coffee every morning in my blender. I make my coffee in a French press. Then I add a big spoonful of coconut oil and a cut a tablespoon of butter and toss it in my blender, mixing it up with my coffee. I make about 24-30 ounces of "bulletproof" coffee in all. I sip it through the day and it makes me feel like a superhero.
So, do a little bit of research, read up a bit about it. See how you like it. Also, be prepared for some stomach-upset. Lots of people get grumbles in the bumbles when they first start drinking "bulletproof" coffee.
Read up about it, try it out, see how you like it.