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 This is This Is Now a Thing, where we check out the science behind new health trends. 
 
 Courtesy of FATwater 
 
 The thing: A $3.95 bottle of water mixed with fat, a sweetener and some flavors. The new 20-calorie beverage, called FATwater, was developed by entrepreneur Dave Asprey, creator of the Bulletproof Coffee craze that still has people adding large amounts of butter and oil to their coffee in the hopes of losing weight. FATwater isn’t a weight-loss drink, per se (each bottle contains 2 grams of fat). Rather, the company bills its product as an alternative to sugary coconut waters and energy drinks. 
 
 Asprey says he uses a patented process to take purified water and mix in tiny droplets of “Bulletproof XCT Oil”: medium chain triglycerides (MCTs) derived from coconut oil. “The water looks kind of iridescent, pearlescent,” Asprey tells TIME. “It has these tiny, invisible droplets of fat that your body really, really likes.” FATwater can be bought bottled or in a concentrated gel that you mix with water yourself. 
 
 MORE: Bamboo Water Is Now a Thing 
 
 The hype: Asprey says FATwater is more hydrating than plain water because the nanoparticles of fat “bring the water into the cells more effectively.” He adds: “Drink a glass of water, and some of it will absorb and some of it won’t. But when your body sees that fat, it says, ‘Oh, come on in, this is pure energy.’ It brings the water in with the fat.” 
 
 Plus, he says, “you get a little bump of energy.” 
 
 The bottle says this: “XCTs follow a special metabolic pathway to burn fat instead of storing it,” the label reads, while giving your body “the clean, high quality fuel it needs—and nothing else.” The bottle also includes this disclaimer, which is required by federal law: “These statements have not been evaluated by the Food and Drug Administration.” 
 
 The research: It is true that medium chain triglycerides are digested differently than other fats, says Marie-Pierre St-Onge, PhD, assistant professor in the department of medicine at Columbia University’s Institute of Human Nutrition and a researcher of MCTs. Instead of being stored into fatty tissue to be used for energy later, they’re typically just burned off. 
 
 But does that mean they give you energy? “It’s actually the opposite,” St-Onge says. “You don’t have the energy—you’re not storing it—so you’re burning it. It’s not useful energy.” 
 
 Where MCTs are useful, St-Onge says, is when you use them to replace another fat (cooking with a little coconut oil, for instance, instead of butter or olive oil). In one study by St-Onge lasting 16 weeks, people who consumed 18-24 daily grams of medium chain triglycerides lost more weight than people who ate the same amount of olive oil. 
 
 “The type of fat that’s used in FATwater increases overall thermogenesis, which is fat-burning in the body,” Asprey says. But St-Onge, who’s own research has shown that MCT oil does enhance diet-induced thermogenesis compared to longer-chain fats, is skeptical that 2 grams of MCT oil—the amount found in FATwater—would have any impact on fat burn. She used a minimum of 18 grams all the way up to 60 grams in her research. 
 
 And what about the notion that MCTs shuttle water more effectively into the body than water ever could alone? 
 
 We asked David Julian McClements, professor in the department of food science at University of Massachusetts Amherst, who says he makes his own fat-infused emulsions all the time for research. Adding drops of oil to water infused with supplements like beta carotene, he’s found, helps your body make use of those nutrients. But improved hydration is not one of the established benefits of MCT emulsions like these, McClements says. 
 
 When asked about it, Asprey says he’s aware of the lack of research. “We’re working on specific studies for these exact formulations,” he says. 
 
 The taste: When TIME’s health team tried the berry and lemon flavors of FATwater, which are sweetened with xylitol, no one could agree on what it tasted like. One reporter thought it tasted “like lotion”; another thought it tasted like the sweet innards of liquid-filled chewing gum; and another said it tasted like “sweetened room water”—a glass of water that’s been sitting out and collects dust or other particulates from the air. 
 
 Though you’re not supposed to be able to detect the fat, one writer said: “I feel like something’s coating my tongue in a not-pleasant way.” 
 
 The bottom line: Water hydrates the body just fine on its own, St-Onge says. “If you’re thirsty, drink water,” she says. “If you’re hungry, eat food.” 
 
 Read Next: Charcoal Juice Is Now A Thing ||||| Oil and water don’t mix — so why are there drops of fat in the newest bottle of H2O? 
 
 Because the Silicon Valley techie who mixed butter with coffee and created a diet he calls “Bulletproof” put them there. He thinks his new drink — yes, it’s called FATwater — is better than real water. 
 
 “My whole career in Silicon Valley has been about disruptive technology,” says Dave Asprey creator of FATwater and an early cloud computing pioneer. “This is a disruptive technology for beverages.” 
 
 This is the only kind of water you should drink, some experts say. (Jorg Greuel/Getty Images) 
 
 The secret ingredient in FATwater is teeny droplets of fat extracted from coconut oil in Asprey’s proprietary process. The oil helps the water do its job better because cells are more likely to take in H2O that has a tiny bit of fat in it, he says. 
 
 Meanwhile, the fats in the oil provide a temporary energy boost and does not get stored as body fat in the way sugar does, he adds. 
 
 Dave Asprey (Courtesy Bulletproof) 
 
 Besides, it’s only two grams of saturated fat — the equivalent of two squares of Chocolove dark. 
 
 “The oils enhance thermogenesis, which is a fancy word for ‘fat burning,’ ” says Asprey, 42. “They get burned as energy and have an appetite-suppression effect. It’s not like we put in sunflower oil or canola.” 
 
 For now, Asprey is selling FATwater only at his Bulletproof Coffee Shop in Santa Monica, Calif., and at an L.A. natural foods store. But he has plans to expand nationally. 
 
 Nutritionists say he shouldn’t rush — this oil is of the snake variety. 
 
 “It is just getting crazier and crazier,” says Rochelle Sirota, a dietitian and nutritionist. “What is the need? Coconut water can be very hydrating because of the electrolytes, but I do not get this whole thing.” 
 
 America’s lone water sommelier, Martin Riese, does not consider FATwater water. “It’s a ‘near water product,’” he sniffs. (© Mario Anzuoni / Reuters/REUTERS) 
 
 Nutritionists at Brown & Medina in Manhattan also questioned FATwater’s claims, saying in a statement that the small amount of fat diluted in the water “would most likely not have an impact on fat burn.” 
 
 There is “no research on the fat being more hydrating,” the statement continued. 
 
 The country’s sole water sommelier, Martin Riese, who offers 20 mineral and spring waters at Ray’s & Stark Bar in Los Angeles, was aware of FATwater — and doesn’t think much of it. 
 
 “Water should not have any calories and this has 20,” he says. “This, I say, is a ‘near water product.’ I believe water should come from nature and not a factory.” 
 
 Though Asprey is not the first to extract the oil, he is the first to mix it in water, patent and market it. 
 
 Research, smesearch, Asprey suggests. 
 
 He cites his creation of Bulletproof Coffee as evidence that conventional wisdom is wrong and that everything — even nature itself — can be improved upon. 
 
 “Biohacking is taking control of the environment around you so you have control of your biology,” he says. “So you are less stressed and recover better and are a nicer person. I am making it easier for people to make those little changes and feel good all the time.” 
 
 Sidebar: Fat Water in the Taste Kitchen 
 
 Tasters found FATwater lacking. 
 
 We sent a bottle of lemon and berry flavors of FATwater into the Daily News Taste Kitchen — and about the nicest thing anyone said is that FATwater is an acquired taste. 
 
 One reporter thought the berry tasted like “liquid soap,” while another thought the lemon was “like Crystal Light not fully diluted.” 
 
 Two testers physically shook with revulsion. But one took a deep sip, swallowed, and gave FATwater its highest praise: “You know what? It’s not that bad.” ||||| If you aren't drinking your own Bulletproof/butter coffee right this second then it's like you don't even know about things that everyone is doing now. So let's talk more about this new trend that is not really new but looks to be headed straight for a mainstream near you. 
 
 What is butter coffee? 
 
 Butter coffee is brewed coffee blended with butter and something called MCT oil, which stands for medium chain triglycerides and is comprised of the fat from coconut/palm kernel oil. Bulletproof® coffee is a brand of coffee created in 2010 by Dave Asprey, an entrepreneur in Silicon Valley who, legend has it, was "literally rejuvenated" after being given yak butter tea by locals after hiking in Tibet in -10 degree weather at 18,000 feet. (A new company in Los Angeles has a Kickstarter going to fund their own instant butter coffee, called Coffee Blocks, which adds egg yolks to the mix, and Bulletproof does a Keurig-compatible cartridge, too.) 
 
 And it's really just butter and that MCT stuff? 
 
 This is the recipe: 
 
 1 cup of black coffee 
 
 1 to 2 tbsp of unsalted grass-fed butter 
 
 1 to 2 tbsp of MCT oil 
 
 Blend until frothy (about 20-30 seconds) 
 
 There's a more detailed explanation of all the variations on making it here, and some folks still added sweeteners like almond milk/honey/cinnamon. The butter is said to be critically, crucially, do-not-fuck-this-up important, and must be unsalted and grass-fed (not simply "organic"). It can't be some Country Crock, k? There is a brand called Kerrygold that people swear by. And the coffee should be "good coffee," meaning at least organic, ideally single-origin beans. In the Bulletproof world, there is a proprietary coffee blend sold called "Upgraded Coffee" that is said to have low mycotoxins, which is basically mold-free (but even paleo types argue that most commercially sold coffee ought to be mold-free already, or only have unconcerningly low levels, and so maybe this thing is a bullshit thing). 
 
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 Is it 'spensive? 
 
 You betcha! At least, it seems to cost more than trad-coffee. Bulletproof says it's only .47 a cup if you buy a ¾ lb bag for $18.95. But a roughly 1 lb. bag of single-origin coffee at my local Groundwork is in the $12-$15 range. Plus, you'll be adding butter that runs $4.99 per 8 oz. to it, and a big jar of MCT oil — enough for a few months, probably, is around $15 (and the Bulletproof brand is twice that much, at $29.95). 
 
 What does it do? 
 
 People say it does a lot of things: Helps with energy and focus. Gives you greater mental clarity. Gives you a coffee buzz but without the jitters or acid-stomach feeling. Sustains your energy over a longer period of time (six hours). Keeps hunger at bay. Aids in weight loss. Makes you high performance. MAKES YOU BULLETPROOF. 
 
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 Is this like a paleo thing? 
 
 Yup. Says Muscle Mag, who notes that a holistic health guy named Paul Chek has been recommending butter coffee for a decade already to his clients: 
 
 It is particularly popular in ancestral-diet circles — followers of the caveman type of eating that advocates mostly animal proteins, fats and vegetables, and those who engage in intermittent fasting. Top performers from the Los Angeles Lakers to MMA fighters to competitive strength athletes swear by it. 
 
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 and: 
 
 Chek's discovery was different than Asprey's. He was looking for a way to couple nutrition with coffee and reduce the magnitude of blood-sugar swings from caffeinated beverages. An avid espresso drinker, he found the single shots gave him extra energy and mental clarity, but also led to quick adrenal fatigue that wrecked the recovery phase between his workouts. "I began to explore different fat sources as a means to reduce the caffeine hangover effect and found butter worked the best," he says. 
 
 But aren't there any other famous people doing it that can make me feel more glamorous for trying it? 
 
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 Of course. Free-spirited nymph Shailene Woodley thinks it's the greatest thing evs: 
 
 And uh, that band Third Eye Blind. 
 
 Is it gross or what? 
 
 Depends on how you feel about having buttery lips first thing in the a.m. Because it's hot and frothy and creamy, it is a lot like drinking a latte, only more buttery/oilier. 
 
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 And even though it's got fat and tons of calories, it's "healthy"? 
 
 Here's where it gets interesting. A cup of this stuff is, depending on how much of the butter and MCT oil you're using, ranges between 200-500 calories, and 45 to 65 fat grams, most of which is saturated fat, and all that adds up to a very dessert-like breakfast (compared to the, say, 480 calories/20 fat grams in a Starbucks Salted Caramel Hot Chocolate). 
 
 This could be beneficial and/or risky: 
 
 "There is some evidence that regular consumption of MCTs can induce very mild fat loss over time," says Christopher Ochner, Ph.D., research associate at The New York Obesity Nutrition Research Center at St. Luke's-Roosevelt Hospitals. "MCTs may also help regulate cholesterol levels, but the types of coconut oils and things from which people typically try to get MCTs often contain dangerous amounts of trans and saturated fats," says Ocher, who notes that 1 tablespoon of grass-fed butter and 1 tablespoon of MCT oil adds up to more than 100 percent of your recommended daily allowance of saturated fat. 
 
 "It's an extra 200-300 calories, so it has to replace some food or another caloric beverage," he says. "Otherwise, you would gain an extra 20 to 30 pounds each year by having a cup per day." 
 
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 That said, there are wellness experts and doctors on record saying to go for it. Andrew Weil, MD, wrote last year that, in light of the adding of butter to hot drinks being commonplace the world over, and because of the misguided campaign against saturated fats, he thinks: 
 
 Blending a tablespoon or so of high-quality, unsalted, organic butter into your morning coffee or tea is unlikely to do you any harm, and is a worthwhile experiment for the sake of both taste and health if you are inclined to try it. 
 
 In so much as you think daily caffeine is OK for you as it is, and assuming you agree "good fats" like butter and coconut oil are also OK (or not so different than adding, say, grass-fed cream to coffee), then there are some nutrients here alongside your caffeine jolt (except in this case, more like a caffeine stretch) that could make for a pleasant experience. 
 
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 Is it supposed to be a meal replacement? 
 
 Some people use it to replace breakfast entirely, while others simply use it as a hunger-minimizer and add a light breakfast a bit later. 
 
 So, butter coffee for everyone! 
 
 The more popular Bulletproof coffee gets, the more people are beginning to warn against possible risks. For one thing, they say a more traditional breakfast is likely to be more nutritious overall than butter coffee. Even folks who agree saturated fat was "unfairly demonized" say that such fat should be eaten WITH a meal and not AS the meal. It can raise cholesterol in some folks. 
 
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 However! Even nutritionists such as NYC nutritionist Amy Shapiro, RD, who say you can benefit from the fats in the drink and the longer-lasting energy, still caution against "just anyone" doing it: 
 
 …if you're not eating a low-carb, Paleo-style diet and are packing in carbs and sugar to begin with, your body may store the fat instead of using it for energy. "This can add a lot of high-fat calories, if the rest of your day doesn't consist of clean eating," she says. In other words, maybe don't pair your butter-coffee with a stack of pancakes. 
 
 If you're concerned about how you'd do on the stuff but want to try it, you could always go get bloodwork done and see where you're at, cholesterol-wise, and then check back in after trying it for a while and make sure it's not doing any harm. 
 
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 Have you tried it? 
 
 Indeed. Some friends who are pretty devoted to it gave me a test run over the weekend. They are both active, fit people who eat really well and are basically vegan. Neither had been drinking coffee for years until they heard of Bulletproof, and wanted to see if it gave them a caffeine boost but without all the crashy/acid-stomach/heart-racing feelings. It did. 
 
 I had a big mug of it, and it tasted like a buttery latte. As it is, I drink pour-over coffee and use coconut milk to sweeten it, so I'm not necessarily looking for a new coffee fix, but I'm interested in sustained energy. I definitely felt a more even-keeled buzz that lasted longer, and never had any distinct feeling of crashing or needing a boost later on. But the main thing I noticed was how filling it was, so much so that it made me want to eat really light food for the remainder of the day — fish and vegetables at lunch and a light salad for dinner. So though I would probably not use it on the daily or skip meals with it, I can see doing it every now and then if it resets your relationship to food, a thing I am a big fan of doing every now and again. 
 
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– Remember that guy who started the Bulletproof Coffee fad, where people add butter and oil to their cups of joe in the hopes of losing weight? Well he's at it again, this time with what the Silicon Valley techie calls "a disruptive technology for beverages," reports the New York Daily News. It's called FATwater, and creator Dave Asprey swears it's better than real water because it is infused with tiny droplets of fat extracted from coconut oil (he's patented this) that improve both hydration and fat burning. The cloud computing pioneer calls it "biohacking," or "taking control of the environment around you so you have control of your biology," he says. "You are less stressed and recover better and are a nicer person. I am making it easier for people to make those little changes and feel good all the time." Not so fast, say the experts. "It is just getting crazier and crazier," one nutritionist says. "If you’re thirsty, drink water; if you’re hungry, eat food," Dr. Marie-Pierre St-Onge, who researches medium chain triglycerides (MCTs) at Columbia University’s Institute of Human Nutrition, tells Time. Asprey himself concedes that there isn't much research in this area, but he says he's got plenty of anecdotal evidence that because MCTs are digested differently than other fats, you do "get a little bump of energy." But St-Onge says he's actually got it backward because they're just burned off. "It's not useful energy." She adds that the 2 grams of fat in a bottle isn't close to enough to improve fat-burning. Meanwhile taste testers at both the Daily News and Time were unimpressed, describing the water as tasting like "lotion," "sweetened room water" that's gotten dusty from sitting around, and "liquid soap." FATwater is currently being sold in Santa Monica and Los Angeles. (Even asparagus water was a thing this summer.)