Even if you didn’t notice it at the time, you’ve probably seen Flat Tummy Co. swag on your Instagram feed. Its millennial pink and gray packets and bottles are ubiquitous on the social media platform, thanks to celebs like the Kardashians and influencers singing their praises alongside sports bra selfies and #sponcon.
The brand promises to bring its “babes,” what they affectionately call their fans and followers, one step closer to a flat tummy via teas that allegedly “detoxify” and “debloat,” lollipops that claim to stifle your hunger, and, most recently, meal-replacement shakes to help you “kick those cravings,” “control your appetite,” and “move those stubborn lbs.”
Founded as Flat Tummy Tea in 2013 by Bec and Tim Polmear, an Australian couple with marketing backgrounds, the company later expanded to become Flat Tummy Co., which now has a following of 1.7 million on Instagram. The Polmears credit the brand’s success in part to an algorithm targeting women in their 20s and a “very unique social media marketing strategy,” per their company website (cue the pretty donuts, Starbucks pink drinks, and pastel sneaks). Despite its popularity, however, Flat Tummy Co. faces controversy on the reg from body-positive advocates like actress Jameela Jamil, who frequently calls out the Kardashians for promoting the products.
Thing is, even if you know that detox teas, which feature an herbal laxative as their first ingredient, are bullshit and that suppressing your appetite is generally a bad idea, the shakes might seem like a harmless way to eat a quick, protein-packed meal…all while losing weight. (As one Insta commenter writes: “I’m expecting my first flat tummy shakes sometime next week, and I am so anxious to see what happens! I just wanna lose these love handles I got over the last few months and get rid of this tiny gut. @flattummyco I hope it works.”)
Before downing one, though, here’s what doctors really want you to know about those celeb-sponsored dranks. (Representatives for Flat Tummy Co. did not respond to Cosmopolitan‘s request for comment.)
Back Up. Is Any Kind of Weight-Loss Shake Ever a Good Idea?
The drink-as-a-meal strategy has been around almost as long as people have wanted to lose weight. In the early 1960s, a weird pink drink named Metrecal hit the scene with Mad Men-looking ads, followed by SlimFast in the 1980s.
One of the reasons this strategy still exists is because they can be a healthy way to drop pounds…but only if the shake has all the macronutrients, calories, and vitamins you need to avoid nutritional deficiencies, says Holly F. Lofton, MD, director of the Medical Weight Management Program at NYU Langone Health. And, ideally, you have a medical professional keeping tabs on you.
For most people, though, this tactic isn’t great for long-term progress, says nutritionist Keri Gans, RDN. “With most shake brands, you’ll probably lose weight quickly, but once you resume normal eating, you will almost definitely gain it back,” she says. That’s partly because swapping your go-to meals for these smoothies doesn’t teach you to incorporate more fruits, veggies, healthy fats, and lean protein into your diet, says Gans. And keeping up with a diet rich in those food groups = healthy, sustainable weight loss, she adds.
Plus, anything that can be used as an excuse to skip a meal puts you at risk for developing new or triggering old disordered eating habits, says National Eating Disorders Association CEO Claire Mysko, especially for people who struggle with their body image.
OK, So What the Hell’s Even in the Flat Tummy Shakes?
Keep in mind that the Food and Drug Administration doesn’t keep an eye on powders, tablets, capsules, or other products containing vitamins, minerals, herbs, amino acids, enzymes, and other supplements, per the National Institutes of Health. And since everything Flat Tummy Co. sells is a supplement, there’s no way to know if the self-care swag’s ingredients are accurate or if other random stuff’s up in there too.
But, going by what the labels say, the Shake It Baby packets are a powder you mix with water or whatever and apparently contain 20 grams of plant-based protein, 50 fruits and vegetables, and something called Super CitriMax—an ingredient the company suggests makes their protein juice “three times more effective than diet and exercise alone.” The brand recommends replacing one to two meals a day with a shake for two to four weeks.
The problem? Each serving contains no more than 140 calories—barely enough for a quick bite, let alone a meal, says Dr. Lofton. At best, the shakes might make decent snacks, thanks to their protein content, she says. (But would you want to pay $89 for four weeks of snacks? JW.)
Onto the matter of shitting your pants: Shake It Baby lists magnesium oxide, a supplement commonly used as an antacid or laxative, on the label. (Ever heard of Milk of Magnesia?) “If you’re constipated, it will help you poop better,” says neurogastroenterologist Kyle David Staller, MD, MPH, who reviewed the ingredients listed on Flat Tummy Co.’s site. But if you’re not, you’ll likely go a lot more often than you’d like. Whether you get to a bathroom in time is, uh, hard to say.
As for Flat Tummy’s alleged weight-loss ingredient—aka hydroxycitric acid (HCA) from the fruit rind of the garcinia cambogia plant—only five legit studies (meaning randomized and controlled) have looked at it over the last 50 years. In other words: When it comes to HCA’s magic, the science just isn’t there.
In a review of previous studies of garcinia cambogia, published in the Journal of Obesity, researchers reported that some studies found minor weight-loss benefits after two to 12 weeks, but the supplement wasn’t any more effective than a placebo.
Plus, in the same review, researchers reported a few instances of side effects like diarrhea, dizziness, headache, and, in rare cases, liver failure and hypomanic behavior. Translation: Researchers don’t know a ton about garcinia cambogia—including how much you’d need to experience side effects, and whether you’d feel them right away or only after a specific period of time—but what they do know isn’t pretty.
Though Flat Tummy doesn’t advertise their shakes as a method for de-bloating, tons of influencers say it helped them feel less puffy. Unfortch, that theory doesn’t really check out, either.
Flat Tummy shakes are packed with FODMAPs, or fermentable oligo-, di-, mono-saccharides and polyols—carbohydrates that don’t digest completely and wind up in our colon, where they ferment and produce gas, aka bloat, in most people, says Dr. Staller. The biggest FODMAP culprit in Shake It Baby is inulin, a type of plant-based fiber—and the second major ingredient in almost every flave (it clocks in at number four for chocolate, which, FWIW, is a fave of Kim’s). “If you’re worried about bloating, eating extra-high FODMAP foods like these shakes is definitely a step in the wrong direction,” he says.
The TL;DR Recap
Despite the lack of scientific support, some users might shed pounds and notice a temporarily flatter belly, but that’s prob due to the laxative ingredient or the unhealthy calorie deficit the shakes create—rather than losing fat, which is the goal of weight loss, says Dr. Lofton. It’s possible HCA could be working, but the science doesn’t really support it, so it’s hard to say for sure.
Even if the evidence isn’t conclusive, if something may cause side effects as serious as liver damage, why risk it?
What might be more dangerous is pervasive non-expert diet and nutrition advice. After all, you’re more likely to run into eating tips from Kim Kardashian than find yourself in a registered dietitian’s office.
“Since our culture is shifting away from diets, women who want to lose weight are closeted,” says Gans. “But if a celeb is using a diet product, it makes them feel less ashamed, so they buy it.”
So until the rich and famous start promoting broccoli and brown rice on their ‘gram, do us a favor and skip their eating advice, K?
For more information on eating disorders and resources that can help, visit the National Eating Disorders Association or the National Association of Anorexia Nervosa and Associated Disorders. If you need to talk to someone right now, call NEDA’s hotline at (800) 931-2237 or text “NEDA” 741-741 to connect with a trained volunteer at Crisis Text Line.