FULL CLAIM: Apple cider vinegar and thermogenic supplements are effective for rapid weight loss
Posts promoting a weight loss beverage went viral on Facebook in May 2022. Multiple Facebook pages shared similar video clips of a cup containing a dark tea in which someone poured a spoon of apple cider vinegar and a spoon of an unidentified white powder. All the videos showed exactly the same glass and dosing spoons and seemed recorded at the same location. Many also contained the same text claiming to have lost 45 kilograms without diet and exercise after a simple “10 second liquid hack”.
The pages that published the clip appeared related to a variety of topics, including wellness, sports, vehicles, and pets. Clicking on the “Learn More” button on these pages led to several different websites registered to Japanese and Vietnamese internet service providers. All the domains were registered in May 2022, and their only content was a testimonial from a woman claiming to have lost an incredible amount of weight.
The websites ran an Amazon ad for a dietary supplement containing caffeine, green tea, and the amino acid derivative L-carnitine. These ingredients are claimed to have a thermogenic effect, that is, to increase the amount of calories that the body burns in metabolic processes. Most of these ingredients are supposed to increase the release or reduce the breakdown of adrenaline, a hormone involved in the use and distribution of stored fat. The hypothesis is that these supplements lead to weight loss by boosting metabolism, reducing appetite, and/or reducing the amount of fat that the body stores.
But as we explain below, the claims that thermogenic supplements and apple cider vinegar are effective strategies for quickly losing large amounts of weight are widespread but unsubstantiated by scientific evidence. The use of scientifically unsubstantiated claims and the lack of transparency on the part of those posting these ads are signs of dishonest marketing tactics and suggest that these posts might be part of a viral scam.
Vinegar is a sour condiment that results from a two-step fermentation process. First, yeast converts the natural sugar present in some foods, like rice or fruits, into alcohol. A bacterium, generally from the genus Acetobacter, is then used to convert this alcohol into acetic acid.
Vinegar has been historically used to flavor foods, as a preservative, and as a home remedy. In recent years, apple cider vinegar has been widely promoted as a “detox” ingredient and a health booster, either on its own or combined with other ingredients such as baking soda and L-carnitine. Claims about the health benefits of apple cider vinegar go from making you lose weight to treating diabetes and even curing cancer.
However, there is little scientific support for most of these claims. There is no research on the effect of apple cider vinegar mixed with supplements or baking soda on weight loss. A few small studies have evaluated the effect of apple cider vinegar on weight loss, but evidence supporting a benefit is weak.
Not all research designs provide the same quality of evidence. Large-scale, double-blind, randomized controlled trials are considered the gold standard for evaluating the efficacy of a treatment. Such design allows researchers to reduce biases and control for confounding factors, such as differences in demographics or physical activity, which could otherwise be wrongly associated with the treatment. However, many of the studies on apple cider vinegar lack blinding, don’t include an adequate control group, or are limited to specific groups of people. In addition, the small number of participants involved in these studies is unlikely to produce conclusive results.
In 2009, researchers in Japan administered none, one, or two daily tablespoons of apple cider vinegar to the regular diet of 155 obese adults. After three months, the researchers observed that the groups consuming vinegar had lost one to two kilograms and had a slightly lower blood triglyceride level and fat mass. These results suggest that, at most, apple cider vinegar might have a modest effect on weight loss. But the study is still too small to be conclusive. It is also unclear whether these results would apply to other populations with diets that are very different from that in Japan, both in terms of calorie intake and type of foods.
In 2018, another small trial studied the effect of apple cider vinegar combined with a low-calorie diet on body weight and blood cholesterol and triglyceride levels in 39 obese volunteers. After three months, all the participants lost weight, but the group consuming apple cider vinegar lost about one kilogram more compared to those who didn’t. However, the design of the study and the small number of participants make these results inconclusive.
Proponents of apple cider vinegar claim that vinegar makes you lose weight by reducing appetite and insulin levels. The authors of the 2018 trial did observe that the group consuming vinegar showed less appetite compared to those who didn’t consume vinegar. A 2013 randomized controlled trial in the U.K. testing palatable and unpalatable vinegar found that the effect of vinegar on appetite control was related to the feelings of nausea caused by drinking vinegar. However, it is unclear whether the slightly sweet apple cider vinegar produces the same effect.
There is some evidence suggesting that apple cider vinegar might lower after-meal blood sugar levels in healthy people and in type 2 diabetic patients[6,7]. However, these are small studies that only showed temporary, modest effects on blood sugar level. And in general, these studies detected effects from vinegar only after consumption of high-glycemic level meals, that is, meals that tend to raise your blood sugar to a high level quickly. This effect didn’t occur in the case of low-glycemic index meals.
Overall, these results suggest that while there might be some benefits to consuming apple cider vinegar, these are modest and unlikely to produce the miraculous levels of rapid weight loss that these Facebook posts claimed apple cider vinegar can produce. The benefit observed in these studies was also limited to certain situations, such as in diabetic patients, and therefore not generalizable to everybody. Furthermore, the quality of evidence is low, and drawing a definite conclusion requires larger and well-controlled clinical studies. A systematic review published in the European Journal of Nutrition in 2020 analyzed the effect of apple cider vinegar on body weight and metabolism from 12 previous studies in animals and 13 in humans. The study concluded:
“Due to inadequate research of high quality, the evidence for the health effects of AV is insufficient. Therefore, more large-scale, long-term clinical studies with a low risk of bias are needed before definitive conclusions can be made.”
Consuming large amounts of apple cider vinegar can also have side effects and contraindications due to its high acidity. For example, vinegar can erode the tooth enamel, irritate the throat, and interact with certain medications, including diuretics and insulin.
Some studies do show that ingredients like caffeine, L-carnitine, and green tea might increase metabolism[9-11]. But whether this effect makes a meaningful difference in weight loss remains unclear as studies have produced mixed results[12-15]. A 2012 Cochrane systematic review of randomized controlled clinical trials concluded that the effect of green tea in overweight and obese adults induced “a small, statistically non-significant weight loss” that is “not likely to be clinically important”.
Another review published in 2020 analyzed published literature about commonly-marketed supplements for weight loss from 2006 to 2016. The authors concluded that these supplements were “unlikely to contribute to meaningful weight loss” and in some cases may cause “extreme side-effects such as liver and kidney failure”.
Overall, the results from these studies don’t suggest that thermogenic supplements cause large weight loss. Furthermore, supplements aren’t subject to the same strict regulations for safety and efficacy as medicines. Some might contain questionable ingredients, and the U.S. Food and Drug Administration found many of them to be downright dangerous due to the presence of hidden active ingredients.
In short, apple cider vinegar may be a healthy addition to the diet. While more research is needed to better assess the effect of apple cider vinegar on weight loss, consuming vinegar alone is unlikely to have a significant impact on weight. There is also no compelling scientific evidence suggesting that thermogenic ingredients are highly effective for weight loss, contrary to claims on social media. In addition, some commercially available supplements have been found to cause dangerous side effects.
To date, there is no known weight control method that produces significant weight loss within a short time without requiring a person to reduce their caloric intake or increase their physical activity. The U.S. Centers for Disease Control and Prevention reminds us that lifestyle changes, including a balanced diet and regular physical activity, are more effective at keeping weight off in the long term.
UPDATE (26 May 2022):
This review was updated to add further context regarding thermogenic supplements, including seven scientific references (1 and 11 to 16 ).
- 1 – Battram et al. (2005) The effect of caffeine on glucose kinetics in humans – influence of adrenaline. The Journal of Physiology.
- 2 – Yamada and Yukphan (2008) Genera and species in acetic acid bacteria. International Journal of Food Microbiology.
- 3 – Khezri et al. (2018) Beneficial effects of Apple Cider Vinegar on weight management, Visceral Adiposity Index and lipid profile in overweight or obese subjects receiving restricted calorie diet: A randomized clinical trial. Journal of Functional Foods.
- 4 – Darzi et al. (2014) Influence of the tolerability of vinegar as an oral source of short-chain fatty acids on appetite control and food intake. International Journal of Obesity.
- 5 – Östman et al. (2005) Vinegar supplementation lowers glucose and insulin responses and increases satiety after a bread meal in healthy subjects. European Journal of Clinical Nutrition.
- 6 – Johnston et al. (2004) Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin Resistance or Type 2 Diabetes. Diabetes Care.
- 7 – Liatis et al. (2010) Vinegar reduces postprandial hyperglycaemia in patients with type II diabetes when added to a high, but not to a low, glycaemic index meal. European Journal of Clinical Nutrition.
- 8 – Launholt et al. (2020) Safety and side effects of apple vinegar intake and its effect on metabolic parameters and body weight: a systematic review. European Journal of Nutrition.
- 9 – Hursel et al. (2011) The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis. Obesity Reviews.
- 10 – Belza et al. (2006) Body fat loss achieved by stimulation of thermogenesis by a combination of bioactive food ingredients: a placebo-controlled, double-blind 8-week intervention in obese subjects. International Journal of Obesity.
- 11 – Serban et al. (2016) Impact of L-carnitine on plasma lipoprotein(a) concentrations: A systematic review and meta-analysis of randomized controlled trials. Scientific Reports.
- 12 – Pooyandjoo et al. (2016) The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials. Obesity Reviews.
- 13 – Hursel et al. (2009) The effects of green tea on weight loss and weight maintenance: a meta-analysis. International Journal of Obesity.
- 14 – Jurgens et al. (2012) Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database of Systematic Reviews
- 15 – Tabrizi et al. (2018) The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials. Critical Reviews in Food Science and Nutrition.
- 16 – Wharton et al. (2020) The safety and effectiveness of commonly-marketed natural supplements for weight loss in populations with obesity: A critical review of the literature from 2006 to 2016. Critical Reviews in Food Science and Nutrition.