Bulletproof coffee. Have you heard of it? Also referred to as butter coffee, it's a growing trend, popularized by Dave Asprey, a technology guru and self-help entrepreneur known as The Bulletproof Executive. The original Bulletproof Coffee recipe calls for 8 ounces of freshly brewed coffee, two or more tablespoons of grass-fed, unsalted butter, and one to two tablespoons of Brain Octane (his blend of coconut oil and palm kernel oil), blended until frothy and creamy.

Other versions call for just coconut oil or just butter, in varying amounts.

The claims: Bulletproof coffee boosts energy and mental focus. Promotes weight loss and prevents cravings. Fuels the body without inflammatory sugars.

While it may seem crazy to put butter into our hot beverages, it's actually a tradition that's been around for ages. Tibetans have been mixing tea with butter for centuries, and in Ethiopia, clarified butter is a common coffee add-in.

How does it taste? I tried bulletproof coffee for the first time last week, making it as close to the original recipe as possible, with two tablespoons of coconut oil and two tablespoons of butter blended into a cup of coffee. And I have to say, I liked it. Not surprisingly, I suppose, because I like both coconut oil and butter, but this concoction certainly tasted better than I was expecting. It was really rich, though; a couple of sips were plenty. (The recipe, by the way, recommends starting with just a teaspoon of coconut oil and one tablespoon of butter per cup of coffee, and gradually increasing to two tablespoons of each.)

As a side note, I quickly learned that a standard immersion blender is way too powerful. After experimenting with my first blend, I was cleaning up buttery coffee all over my kitchen. Better to use a regular blender like you would for smoothies, or a small battery-operated milk frother.

The stats: The above-mentioned recipe for original bulletproof coffee has 430 calories and 50 grams of fat, with no protein or fiber, and trace amounts of vitamins and minerals.

My take on bulletproof coffee: Coffee is one of the top sources of antioxidants in the American diet, and is linked to a decreased risk of type 2 diabetes, gallstones, and Parkinson's disease. It can also help to relieve headaches, improve athletic performance, and boost brainpower. And studies have suggested a link between coconut oil and higher levels of "good" HDL cholesterol.

Plus, several recent studies have indicated that saturated fats like butter and coconut oil may not be as bad for us as we've thought. (It should be noted, however, that health organizations such as the Academy of Nutrition and Dietetics and the American Heart Association still recommend that we limit our intake of all types of saturated fat.)

So. I like to start the day with protein and/or fat instead of sugary carbs, to provide a sustained release of energy and offset cravings, instead of a quick energy surge followed by a sharp crash. And when it comes to coffee add-ins, I prefer fat over sugar (I often recommend that clients use a tablespoon or two of real half-and-half instead of sugar-laden powdered creamers or flavored liquid creamers), for these same reasons.

But for most people, 430 calories is pretty steep for a morning cup of joe.

And if your 430-calorie coffee is taking the place of your usual breakfast, that means you're not getting the protein, vitamins, minerals, or fiber that you would be getting with a breakfast like plain Greek yogurt topped with fresh berries or a veggie-packed omelet.

I've written before that I use a low-carb, naturally sweetened protein drink (half of an ICONIC ready-to-drink) in place of milk or cream in my morning cup of coffee, starting my day off with 10 grams of protein and 65 calories and 1.5 grams of sugar. And even though I liked the taste of bulletproof coffee, the protein drink just works better for me and sustains me until I have a more substantial breakfast a few hours later.

If you're interested in trying out the fat-in-your-coffee trend, my recommendation is to go with just a tablespoon or so of coconut oil. You'll get 120 calories per tablespoon of coconut oil, and if you pair it with an egg or two, or a carton of Greek yogurt topped with fresh berries, you're still under 300 calories for your coffee and breakfast that now provides a decent bit of fat, along with a good dose of protein, vitamins, and minerals.

For more on this topic, check out Molly's original piece for Nola.com