What a Dietitian Thinks About 5 of the Most Popular Weight-Loss Drinks

Weight-loss drinks are all the rage. It's nearly impossible to get through the day without seeing some sort of ad or influencer promoting the latest shake or #teatoxing beverage. Like many other weight-loss supplements, these drinks promise an easier way to lose weight, speed up metabolism and/or boost energy.

But do these popular weight-loss drinks work?

As an RD, I get a lot of questions about these teas, shakes, drinks, etc. Clients, friends and family are often looking for a quick fix to their weight-loss woes. I decided to dig in on five of the most popular products out there, reviewing their ingredients via the Natural Medicines Database and examining the research backing their claims to see if any of these beverages are an effective strategy for weight loss.

As far as drinks go, Flat Tummy features a shake and two detox teas — Activate and Cleanse. Each involve a two-step process that the company claims will work to "reduce bloating and get that tummy back to flat" while also "boosting energy and speeding up metabolism." It's sold in 2- or 4-week bundles. The company claims the teas are 100 percent natural — and the ingredients are — but do they work?

• Peppermint: This ingredient is effective in reducing bloating in people with irritable bowel syndrome.
• Lemon balm: Preliminary animal research shows that taking a specific combination of herbs including lemon balm reduces body weight in obese mice.
• Licorice: Early research shows that taking a specific licorice flavonoid oil has no effect on weight or body fat.
• Dandelion: This ingredient is used as a diuretic but animal studies have been mixed and there's insufficient evidence in humans.
• Cleavers: Often used as a diuretic yet there is not enough evidence to support its effectiveness.
• Fennel: Evidence suggests fennel may help treat constipation.
• Green tea: There's conflicting research about the effectiveness of green tea for obesity and weight loss. Some research shows a modest improvement in weight loss for people who are overweight or have obesity when they have green tea or green tea extract containing caffeine but conflicting results exist.
• Caraway: Some clinical research shows that taking a proprietary combination of caraway oil and peppermint oil two or three times daily for 4 weeks reduces symptoms of dyspepsia including feelings of fullness.
• Cardamom: Early research in adults who are overweight and have diabetes shows that drinking black tea steeped with cardamom powder does not affect weight or waist circumference.

• Senna: This herb is effective as a short-term treatment of constipation.
• Peppermint: This ingredient is effective in reducing bloating in people with irritable bowel syndrome.
• Cassia chamaecrista: There's insufficient evidence to support this being used as a weight-loss supplement.
  
• Licorice: Early research shows that taking a specific licorice flavonoid oil has no effect on weight or body fat.
• Caraway: Some clinical research shows that taking a proprietary combination of caraway oil and peppermint oil two or three times daily for 4 weeks reduces symptoms of dyspepsia including feelings of fullness.
  
• Dandelion: This ingredient is used as a diuretic but animal studies have been mixed and there's insufficient evidence in humans.
• Rhubarb: There's mixed evidence on rhubarb's effect on obesity.
  

One of the tea's ingredients is senna, which is a laxative that works by irritating the lining of your gut, according to the National Center for Biotechnology Information. This will obviously help with decreasing bloat (but, I mean, it's a laxative).

The shakes claim to be clinically studied, which is misleading because it doesn't appear that the shakes themselves were tested. Instead, it seems they're referring to an ingredient in the shake powder — Super Citrimax or garcinia cambogia. The weight-loss research on this supplement is mixed, according to Consumer Labs — that is, it may work, but it's not a sure thing.

What's more concerning is that of the 13 various garcinia cambogia products Consumer Labs tested, only six contained the amount the supplement claimed. Also, there are side effects and potential drug interactions associated with the supplement.

The Master Cleanse, also known today as the Lemonade Diet, is a modified juice cleanse that claims to result in rapid weight loss. It's been around for almost 50 years.

The actual cleanse lasts for a minimum of 10 days and is centered around drinking at least 6 glasses a day of the proprietary spicy lemonade drink which includes water, lemon juice, maple syrup and cayenne pepper. Tea, water and salt are also allowed.

• Lemon juice: It's often used as a digestive aid and diuretic but there's not enough evidence to support lemon juice's effectiveness.
• Maple syrup: There's no evidence to support using this ingredient as a weight-loss method.
• Cayenne pepper: There's insufficient research to support this ingredient's effect on weight loss.

For short-term weight loss, if you're able to stick with it, yes, you will likely lose weight with the Master Cleanse. But it's not the combination of ingredients per se that drives these results — rather, it's the overall reduction in calories from subsisting on only clear liquids.

Researchers came to the same conclusion after subjects underwent a 7-day lemon and maple water cleanse in a randomized clinical trial published in May 2015 in Nutrition Research. They determined that "the lemon detox program reduces body fat and insulin resistance through caloric restriction."

This "detox tea" from SkinnyFit claims to combine 13 superfoods to help you lose weight, fight bloat, increase energy, flatten your belly and boost your immunity. While there's no official definition of the term "superfoods," it's used loosely here to describe some of the ingredients like stevia, lemongrass and peach flavoring.

• Matcha green tea: Matcha comes from the same plant as green tea extract. There's conflicting research about the effectiveness of green tea for obesity and weight loss. Some research shows a modest improvement in weight loss for people who are overweight or have obesity when they have green tea or green tea extract containing caffeine but conflicting results exist.
• Yerba mate: Research is mixed on the effect of yerba mate on obesity.
• Hibiscus: Tea made from this flower may help with hypertension but there's not enough evidence to support its effect on weight loss.
• Oolong tea: This tea has no impact on weight loss but may help those with high cholesterol and triglycerides.
• Goji berry: There's a lack of sufficient evidence supporting taking goji berry for weight loss.
• Milk thistle: It may help with indigestion but there's not enough research to support any other benefits.
• Ginseng: There's not enough research to suggest ginseng is beneficial for weight loss.
• Lemongrass: More research is needed to understand any weight-loss benefit that may exist.
• Nettle beaf: This ingredient may have some effect on diabetes and high cholesterol, although there's not enough evidence to show any weight-loss connection.
• Dandelion: This ingredient is used as a diuretic but animal studies have been mixed and there's insufficient evidence in humans.
• Guarana: When taken orally, it might cause weight loss when used in combination with other herbs, although the research is limited.
  
• Stevia: This is a low-calorie sweetener.

The ingredients list reads as a blend of teas — green, oolong and matcha — along with some herbs like dandelion leaf, milk thistle and ginseng. The trouble is, there are no quantities listed as you'd typically find with some other teas. The only quantity provided (available on the site) is the amount of caffeine, which is 18 milligrams per serving. For comparison, a cup of coffee has about 100 milligrams of caffeine, according to the USDA.

The trouble with many of these types of drinks is that they promise easy weight loss, when in actuality, none of them offer the easy fix consumers are hoping for.

Another red flag? In fine print at the bottom is copy stating: "Exercise and proper diet are necessary to achieve and maintain weight loss." So yes, you may lose weight while drinking this "detox tea" but changing your diet and exercising are required as well.

KETO OS NAT is targeted toward people on the high-fat, extremely low-carb keto diet. The goal of this diet is to reach ketosis — in this state, your body uses ketones, a byproduct of fat, for energy in place of glucose, which is derived from carbohydrates, per the Cleveland Clinic. Once in ketosis, your hunger will decrease while your muscle mass increases, according to the Cleveland Clinic.

As well as the ketones your body makes, there are also exogenous ketones — that is, ketones from an external source, such as a supplement — that can help induce ketosis. KETO OS NAT is a type of exogenous ketones, and it claims to promote "favorable fat loss." The theory behind the product is that it helps your body get into ketosis quicker and makes it easier for your body to stay in ketosis.

• R-beta hydroxybutyrate: There's no evidence supporting the ketone body's effect on weight.
• L-taurine: Additional research is needed to understand if there is any weight-loss benefit to this amino acid.
• Fermented L-leucine: There's no compelling evidence to support the use of L-leucine for weight loss.
• Inner bark of uncaria tomentosa: This ingredient is also known as cat's claw, and there isn't scientific evidence it provides health benefits, per the National Center for Complementary and Integrative Health.

There's currently not a strong body of research backing the case for exogenous ketones exclusively and weight loss. For instance, after healthy adults consumed exogenous ketone esters for 28 days, there was no significant change in body weight or composition, fasting blood glucose, cholesterol or triglyceride levels, per a December 2019 study in Regulatory Toxicology and Pharmacology.

However, exogenous ketones in combination with a ketogenic diet will likely lead to weight loss. Diet still plays a huge role in the effectiveness of exogenous ketones — pizza and milkshakes aren't going to cut it. They may help you stay in ketosis if you are actually following a primarily ketogenic diet.

The Skinny Mint 28 Day Fat Burning Coffee is one of a few weight-loss drinks products from Skinny Mint. The product claims to help you "smash your health goals in just 28 days," and "boost energy." It's also reportedly an appetite stimulant.

• Arabica coffee: More evidence is needed to support this green coffee's use with weight loss.
• Panax ginseng: There's not enough research to suggest ginseng is beneficial for weight loss.
• African mango extract: There's not enough evidence to support the use of this extract for obesity.
• Louisa extract: There's insufficient evidence of any weight-loss benefits to this extract (also known as lemon verbena).
• Aloe vera extract: Aloe may help with constipation. There's limited research on its effect on obesity.
• Maqui berry extract: It's used for weight loss although there's not enough science to support its effectiveness.
• Green tea extract: There's conflicting research about the effectiveness of green tea for obesity and weight loss. Some research shows a modest improvement in weight loss in people who are overweight or have obesity when consuming green tea or green tea extract containing caffeine but conflicting results exist.
• L-carnitine: Research is mixed when it comes to the potential weight-loss effects of taking this amino acid.
• Ganoderma extract: While this extract reduced obesity in mice, per a June 2015 study in Nature Communications, further research is required to know if the effect is similar in humans.
• Garcinia cambogia extract: The extract is used for obesity and athletic performance although the results are conflicting. More research needs to be done.
• Chromium picolinate: There's some conflicting evidence about the effect of chromium on weight loss and obesity. However, most evidence shows that taking chromium orally does not significantly improve weight loss.

Aside from green tea extract, there's not a strong enough body of research backing any of the ingredients in this product to support weight loss in humans.

It's also unclear how much you're getting of each of these specific ingredients.

The trouble with many of these types of drinks is that they promise easy weight loss, when in actuality, none of them are the easy fix consumers are hoping for. Changes in diet and lifestyle are still required to see any results. On top of that, these products are expensive and contain ingredients that may have side effects or interactions with certain medications.

A healthier approach is to make sustainable changes to your diet and lifestyle. When it comes to beverages, stay hydrated with low-calorie, low-sugar beverages like water, sparkling water and unsweetened tea.