Should You Be Drinking Fat Water?

The man behind Bulletproof Coffee just launched another one-of-a-kind beverage called FATwater, and it’s exactly what the name implies: fat added to purified water. The self-described "biohacker" Dave Asprey claims his new sugar-free drink offers calorie-burning fuel, easy-access energy, and more efficient hydration — all thanks to specific medium-chain triglycerides (MCTs) from coconut oil.

But is FATwater legit? We weren’t sure, so we dug in to find out.

First of all, there’s only a scant amount of fat in FATwater — just 2 grams, making a 16-ounce bottle only 20 calories — so this is not, nor is it trying to be, a sound dietary source of fat. You still need your nuts, avocados, and eggs.

Asprey put fat in a hydrating beverage because he claims these specific MCTs can help the body produce energy more efficiently than it can with sugar. He says Bulletproof XCT Oil, a patented blend of two fatty acids from the heart of the coconut, follows a special metabolic pathway directly to the liver. There, the MCTs are converted to keytone bodies, which provide ready-to-go fuel, instead of being stored as fat. "It takes the body only three steps to convert these MCTs into energy, whereas it takes 26 steps with sugar," Asprey says. "It’s a strange little trick."

Then there’s the hydration. Your body absorbs water just fine on its own, but because it’s wired to welcome fat, Asprey says Bulletproof XCT Oil may help it more readily accept the water, helping you hydrate better and therefore feel more energized.

According to Marie-Pierre St-Onge, a researcher at Columbia University’s Obesity Research Center, certain MCTs, unlike other fats, do in fact travel directly to liver, so there’s less chance of them turning into adipose tissue. Also, she says MCTs have a higher thermic effect than other fats and foods, meaning it takes more energy to digest them. Therefore, your body ends up holding onto fewer of those calories than it does from sources with lower thermic effects, which is why studies have shown MCTs can promote weight loss.

But whether these metabolic processes translate into usable fuel is less cut-and-dry. St-Onge says the energy needed to digest MCTs is essentially burned off — or "wasted" — so it won’t be there in the long run to power you through a workout. "Consuming MCTs now doesn’t mean you’ll have more energy to go on 10-mile run later," she says. "But on the other hand, when processing foods with an increased thermic effect, you might feel like you are more alert and have more energy."

NUTRITION: Why Experts Now Think You Should Eat More Fat

In other words, FATwater’s claims for the most part check out. It won’t make you fly through a race, but it might make you feel like you have more pep, whether right before a workout or when sitting at your desk midday. And, like any water, FATwater will certainly hydrate you. 

And the taste? It turns out FATwater is delicious. Both the Berry and Lemon flavors are slightly sweet and don’t have that chemical-y artificial-sweetener taste like most flavored waters and low-calorie beverages. And while FATwater (shockingly) doesn’t taste oily in the slightest, the fat does make it taste, oddly, "wet." As Asprey puts it, "it's like the opposite of dry champagne."

Bottled FATwater will soon be available at the Bulletproof Coffee café in Santa Monica, California, and Erewhon natural grocery stores in Los Angeles and Calabasas. Concentrate packets will be sold at bulletproof.com.