Do Artificial Sweeteners Make You Fat?


a woman being weighed

With nearly 40% of the world’s population now classified as obese, and increasing evidence pointing to sugar as the culprit, people are turning to foods that contain low-calorie sweeteners to give them the sweet taste they enjoy, without the risk of gaining weight. However, new research from George Washington University in the US suggests that artificial sweeteners may actually increase a person’s risk of becoming obese.


The obesity epidemic is caused by an increase in fat and sugar in people’s diets. Fat accumulation in obesity increases the chances of getting type 2 diabetes, heart conditions and cancer. As such, new guidelines from Public Health England encourage the public to buy lower calorie and lower sugar products.


So changing our diet to include low-calorie sweeteners, such as sucralose and aspartame, should be a good way to get all the sweet taste without any of the guilt.


Instead, the new study suggests that eating these sweeteners could do the opposite and increase the chance of us accumulating fat in our bodies, in a “dose-dependent” fashion. In other words, the more artificial sweetener you consume, the more fat your body creates and stores.


What they do to your body


For many years, we have known that sweet substances (sugars or artificial sweeteners) bind to sensors in our mouth called “sweet-taste receptors”. These receptors send a message to our brain to tell us that we are eating something sweet.


In the last decade, these sensors have been found in other parts of our body, such as the bladder, the lungs and even in bones. This has raised questions about what effect sweeteners, and these sweet taste receptors, could be having inside our bodies.


The new research, results of which were presented at ENDO 2018, the 100th annual meeting of the Endocrine Society in Chicago, looks at the effect that artificial sweeteners have on the cells that make up our fat stores. These cells have a glucose transporter (a protein that helps glucose get into a cell) called GLUT4 on their surface and, when we eat more sugar, the cells take up more glucose, accumulate more fat and become larger.


The researchers in this latest study found that the artificial sweetener, sucralose, commonly found in diet foods and drinks, increases GLUT4 in these cells and promotes the accumulation of fat. These changes are associated with an increased risk of becoming obese.