By Courtney Lee, MS, RDN, CDN, CLT, CFCS
What’s going on with nonnutritive sweeteners? There are so many claims out there regarding the health benefits or warnings against adverse effects of consuming these products. Reputable professional organizations currently have varying opinions about the use of nonnutritive sweeteners and well-conducted research studies report opposite results at times.
While the evidence is still growing and research is still underway, it is interesting to note that there is a possibility that a physiological change may occur in the body when nonnutritive sweeteners are consumed that could potentially promote weight gain. There are several hypotheses for this possible physiological connection supported in preliminary research at this time. Let’s take a look at them one at a time.
Sweet Taste Receptor Activation
Sweet tasting foods activate sweet taste receptors in the body. This includes nutritive sweeteners (e.g., sucrose, fructose) and nonnutritive sweeteners (e.g., Stevia, aspartame). Sweet taste receptors are located in the oral cavity and throughout the body. When sweet taste receptors are activated in the oral cavity, they release neurotransmitters to the brain, telling the brain that something sweet has been consumed. The response of sweet taste receptors in other parts of the body are not fully understood. We do know that sweet taste receptor activation in the pancreas leads to insulin release and that sweet taste receptor activation in the intestines leads to the release of glucagon-like peptide-1 (GLP-1). These hormonal releases in response to nonnutritive sweeteners could lead to changes in metabolic health and eventual weight gain.
Promotion of Adipogenesis
There are sweet taste receptors located in adipose tissue. Researchers believe that when these receptors are exposed to nonnutritive sweeteners, it promotes adipogenesis, or development of new fat cells. Development of new fat cells could eventually lead to greater fat accumulation and weight gain.
Changes in Relationship Between Sweetness and Calories
Naturally, sweet tasting foods are indicative of calories and nutrients, but this is not the case with nonnutritive sweeteners, which contain minimal calories and nutrients. One hypothesis suggests that the sensation of sweetness without calories and nutrients may result in a disturbance of appetite regulation and metabolic signaling. The idea is that this disturbance could cause someone to have the desire to eat more food since nutrients were not received with sweet tasting foods, eventually leading to weight gain.
Changes in Taste Preferences
Exposure to sweet compounds could lead to a stronger preference for sweet tasting foods. Since many highly sweet foods are also high in calories and nutrients, an enhanced sweetness preference could lead to poor dietary patterns and eventual weight gain.
Changes in Gut Microbiota
We know that nonnutritive sweeteners positively influence the microbial composition of the oral mucosa by promoting anti-microbial activity against periodontal pathogens. We are now learning about the changes that nonnutritive sweeteners may have on the gut microbiota. Studies indicate nonnutritive sweetener consumption can cause glucose intolerance, elevated fasting glucose, and impaired insulin-stimulated glucose disposal. These changes in the gut could lead to metabolic dysfunction and eventual weight gain.
In some studies, nonnutritive sweetener consumption alongside glucose increases the rate of glucose absorption. This could be because of nonnutritive sweetener-induced upregulation of the two main intestinal glucose transporters. This alteration in the metabolic process could lead to eventual weight gain.
Please remember, these are all potential physiological explanations of why nonnutritive sweetener consumption could lead to weight gain. All of these ideas are supported by preliminary research, but more research is needed to support and prove any or all of these ideas in humans. Currently, nonnutritive sweeteners are safe for consumption according to the Food and Drug Administration (FDA) within certain parameters. If you want to learn more about the current evidence about nonnutritive sweetener consumption and body weight, check out the webinar developed by Dietitians On Demand on this topic!
Courtney Lee, MS, RDN, CDN, CLT, CFCS consults locally with Dietitians On Demand and also has a virtual private practice, Kitchen Nutrition, LLC. Courtney enjoys equipping dietitians and dietetic interns with the tools they need for professional success so they don’t have to learn the hard way. Courtney enjoys baking, running, and hosting friends and family in her home.
Find her on Instagram @yourkitchennutrition.
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Sylvetsky, A. C., Rother, K. I. (2018). Non-nutritive Sweeteners in Weight Management and Chronic Disease: a review. Obesity (Silver Spring). 26(4): 635-640
Sylvetsky, A.C. (2018). Metabolic Effects of Low-Calorie Sweeteners: A Brief Review. Obesity. 26: S25-S31.