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Are Artificial Sweeteners Bad For You?

Written by Charlotte Green

Are Artificial Sweeteners Bad For You?

Currently, there is much attention being paid to reducing our sugar consumption, both for our general and metabolic health, especially considering the global rise of obesity and other lifestyle associated diseases such as type 2 diabetes. In fact, one of the most significant risk factors for type 2 diabetes is a Western diet, high in sugar, saturated fat, and processed foods (1). Consequently, in recent years, the consumption of artificial sweeteners has risen dramatically.

What are artificial sweeteners?

Artificial sweeteners are chemical substances which are used a sugar alternative to sweeten food and drinks. Artificial sweeteners can be up to around 600 times sweeter than sugar (in the case of sucralose), meaning they can be used in much smaller quantities (2). They are also known as non-nutritive sweeteners because they generally contain little or no calories.

Where are they found?

There are seven types of sweeteners approved for use in the UK; acesulfame K, aspartame, saccharin, sorbitol, sucralose, stevia and xylitol. These can be found in:

  • Drinks

  • Yoghurts

  • Desserts

  • Sweets

  • Toothpaste

  • Chewing gum

Common sweeteners found in the supermarket include brand names such as Canderel (containing aspartame) and Sweetex (containing saccharin). Stevia, a natural sweetener alterative from the South American plant Stevia rebaudiana, is also becoming a popular sugar alternative.

Despite strict quality controls and food safety standards, there still remains considerable controversy surrounding artificial sweeteners, particularly in the media. As a consumer, it is often confusing to decide whether artificial sweeteners are a healthy choice. Here we will explore the evidence to try and make it a little clearer.

Artificial sweeteners and body weight

Although artificial sweeteners have been used to try to tackle rising obesity, some studies have found that they may in fact contribute to weight gain and inflammation, particularly sucralose (3,4). Artificial sweeteners can bind to sweet taste receptors in the tongue, intestines, and fat tissue, just like sugar. This triggers a variety of signalling pathways to communicate to the brain that food has been consumed and produce feelings of fullness. However, the signals induced by artificial sweeteners are weaker, which may be due to the lack of calories. It has been suggested that this could lead to compensatory consumption of extra calories (5).

Nevertheless, the majority of the research demonstrating that artificial sweeteners may cause weight gain were carried out on animals, which may not represent their action in humans (3). In fact, most human studies show that artificial sweetener consumption is not generally associated with weight gain (6).

Artificial sweeteners and the gut microbiota

Previously it was thought that artificial sweeteners were not broken down by the body and passed through unchanged. However, this is no longer believed to be the case, as evidence suggests that they can be broken down by the gut microbiota (7). The gut microbiota is the community of microorganisms residing in the gastrointestinal tract, necessary for a variety of important processes in the body, from digestion to immunity (8). See more on how we can support our gut microbiota in our posts on prebiotics and fibre.

Some artificial sweeteners, such as sucralose and saccharin, can directly interact with the gut microbiota. The microbiota may be able to utilise artificial sweeteners as an energy source, leading to the growth of these species of bacteria (9). Thus, artificial sweeteners have the ability to modify the composition of the gut microbiota and wider processes in the body (7).

A recent important study investigated the effects of a two-week consumption of a variety of artificial sweeteners in volunteers who had previously been complete abstainers from artificial sweeteners. They found that sucralose and saccharin significantly altered the gut microbiota, causing dysbiosis, an imbalance of the “good” and “bad” bacteria. This change in the gut microbiota resulted in higher blood sugar levels (10), which could be due to inflammation induced by gut microbiota dysbiosis (7).

It is also important to note that some artificial sweeteners may affect digestion and cause uncomfortable gut symptoms such as bloating. Sweeteners ending in "-ol", such as sorbitol and xylitol, often found in sugar-free sweets, are classed as being high in FODMAPs, a fermentable carbohydrate known to cause gut symptoms in individuals with irritable bowel syndrome (IBS) (11). These products should therefore not be consumed in excessive amounts.

Learn more about other types of FODMAPs and a low FODMAP diet here.

Natural vs artificial sweeteners

"Natural" sweeteners, such as stevia are derived from plants where as "artificial" sweeteners are chemical substances. "Natural" sweeteners are gaining popularity, but are they healthier than artificial sweeteners? Evidence seems to suggest that stevia does not have the potential to alter blood sugar levels, unlike some artificial sweeteners (12).

Furthermore, because stevia is derived from the leaves of the Stevia rebaudiana plant, it contains many other compounds besides the sweetener, which may have beneficial anti-inflammatory properties, although further research in human trials is necessary (13).

However, stevia, just like artificial sweeteners, has the ability to modify the gut microbiota, meaning it could have, as yet unexplored impacts on human metabolism (10).

Are artificial sweeteners bad for us?

At the moment, the evidence on artificial sweeteners is still inconclusive. Although some studies show that artificial sweeteners may have detrimental effects on weight, blood sugar control, and the gut microbiota, these studies tend to have been carried out in animals. The results in human trials are much more varied, with some showing a neutral effect on health or even some benefits when considering obesity (14).

The huge variation in conclusions could be due to the type of artificial sweetener investigated, as they all react differently in the body. Therefore, it is not helpful to generalise that all artificial sweeteners are categorically “bad”. It could be that some are more beneficial or detrimental than others. More long-term studies in humans are required to accurately determine the effects they have on our health.

For now, it is important to remember, like most things when considering the diet, moderation is key. Artificial sweeteners are not necessarily something to be feared, and can have a place in a healthy, balanced diet, when consumed consciously.

At TCN our specialist eating disorder dietitians can offer online consultations to support your health journey! Book a free 15 minute discovery call here with one of our dietitians.

Charlotte Green

Charlotte Green

Charlotte Green is a postgraduate Dietetics student at the University of Chester, after graduating with a degree in Biological Sciences from Durham University. She is passionate about the role of nutrition in health and longevity, the gut microbiome and the link between food and mood. Charlotte looks forward to supporting others live a healthier life in her future role as a registered Dietitian.



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  2. Additional Information about High-Intensity Sweeteners Permitted for Use in Food in the United States | FDA [Internet]. [cited 2022 Sep 1]. Available from:

  3. Sánchez-Tapia M, Martínez-Medina J, Tovar AR, Torres N. Natural and Artificial Sweeteners and High Fat Diet Modify Differential Taste Receptors, Insulin, and TLR4-Mediated Inflammatory Pathways in Adipose Tissues of Rats. Nutrients [Internet]. 2019 Apr 1 [cited 2022 Aug 21];11(4). Available from:

  4. Qin P, Li Q, Zhao Y, Chen Q, Sun X, Liu Y, et al. Sugar and artificially sweetened beverages and risk of obesity, type 2 diabetes mellitus, hypertension, and all-cause mortality: a dose-response meta-analysis of prospective cohort studies. Eur J Epidemiol [Internet]. 2020 Jul 1 [cited 2022 Aug 26];35(7):655–71. Available from:

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  6. Laviada-Molina H, Molina-Segui F, Pérez-Gaxiola G, Cuello-García C, Arjona-Villicaña R, Espinosa-Marrón A, et al. Effects of nonnutritive sweeteners on body weight and BMI in diverse clinical contexts: Systematic review and meta-analysis. Obes Rev [Internet]. 2020 Jul 1 [cited 2022 Aug 20];21(7). Available from:

  7. V H, L L, A C-C, J S. Interactions of Non-Nutritive Artificial Sweeteners with the Microbiome in Metabolic Syndrome. Immunometabolism [Internet]. 2022 Apr [cited 2022 Aug 20];4(2). Available from:

  8. Adak A, Khan MR. An insight into gut microbiota and its functionalities [Internet]. Vol. 76, Cellular and Molecular Life Sciences. Birkhauser Verlag AG; 2019 [cited 2021 Jul 1]. p. 473–93. Available from:

  9. Deng Y, Wang Y, Xia Y, Zhang AN, Zhao Y, Zhang T. Genomic resolution of bacterial populations in saccharin and cyclamate degradation. Sci Total Environ [Internet]. 2019 Mar 25 [cited 2022 Aug 21];658:357–66. Available from:

  10. Suez J, Cohen Y, Valdés-Mas R, Mor U, Dori-Bachash M, Federici S, et al. Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance. Cell [Internet]. 2022 Aug 17 [cited 2022 Aug 26]; Available from:

  11. Rinninella E, Cintoni M, Raoul P, Gasbarrini A, Mele MC. Food Additives, Gut Microbiota, and Irritable Bowel Syndrome: A Hidden Track. Int J Environ Res Public Health [Internet]. 2020 Dec 1 [cited 2022 Sep 1];17(23):1–15. Available from:

  12. Farhat G, Berset V, Moore L. Effects of Stevia Extract on Postprandial Glucose Response, Satiety and Energy Intake: A Three-Arm Crossover Trial. Nutrients [Internet]. 2019 Dec 1 [cited 2022 Sep 1];11(12). Available from:

  13. Peteliuk V, Rybchuk L, Bayliak M, Storey KB, Lushchak O. Natural sweetener Stevia rebaudiana: Functionalities, health benefits and potential risks. EXCLI J [Internet]. 2021 Jan 4 [cited 2022 Sep 1];20:1412–30. Available from:

  14. Del Pozo S, Gómez‐martínez S, Díaz LE, Nova E, Urrialde R, Marcos A. Potential Effects of Sucralose and Saccharin on Gut Microbiota: A Review. Nutrients [Internet]. 2022 Apr 1 [cited 2022 Aug 26];14(8). Available from:


Talia Cecchele Nutrition is a team of registered dietitians that specialise in eating disorder recovery, disordered eating, gut health and sports nutrition. We aim to bring balance back to nutrition, help you to break free from food rules and find food freedom. We offer virtual consultations and group programs so whether you are based in London, the United Kingdom or around the world we would love to support you. To enquire about a private consultation please fill out a contact form.

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