Here’s what artificial sweeteners are really doing to your body

It feels like we’re always getting mixed messages about artificial sweeteners. Some researchers claim that they’re just as bad as regular sugars, while others maintain that no-calorie sweeteners, like stevia, are a better choice than real sugar. It can be hard to keep up. 

Dana Small, a researcher at Yale University, might have cracked the code when it comes to knowing what artificial sweeteners are really doing to our bodies.

When she began her research, she wasn’t looking at whether artificial sweeteners are healthy or not, but rather what they do in our bodies.

What she found, in simple terms, is that they confuse our bodies and brains. To complete her study, Small created five beverages with varying amounts of calories. They all had the same sweet factor, but different calorie counts: zero, 37.5, 75, 112.5, and 150 calories. The study subjects drank the beverages over the course of a few weeks, but the initial results stumped Small.

The participants’ brains had the strongest response to the 75-calorie drink — not the low-calorie or even the highest-calorie option. So it wasn’t like more calories meant more reward for the subjects’ brains. The results didn’t make any sense.

Nevertheless, Small persisted for about two more years and finally came to some conclusions about the role of artificial sweeteners in our diets. According to her recent report, when the levels of sweetness and calories were just right, the body metabolized the calories as it should. When the calories were too high for the sweetness level (i.e. that 150-calorie drink) or too low, though, the metabolic rate was all off.

Small said in an interview with Vox, “It’s like the system threw up its hands and didn’t know what to do.”

Taste can change the metabolic fate of calories,” Small added.

So what does this mean for our diets? It looks like a lot of those products we buy that are low in calories, but sweetened artificially (like a diet soda or a fat-free yogurt) confuse our bodies. The calories don’t get burned at all. Sure, there aren’t many of them, but they likely go hide out in the liver, or in muscle or fat, which isn’t “desirable,” Small said. But it does explain some of the findings about diets that are high in artificially sweetened food and their effect on metabolism.

If sweeteners are disrupting how carbohydrates are being metabolized, then this could be an important mechanism behind the metabolic dysfunction we see in diets high in processed foods, Small explained.

There’s another thing to consider, though. When we consume these low-calorie and highly sweetened foods with carbohydrates — like a diet soda with a sandwich — the brain and body are even more confused about what to do with all the calories. When you consume them alone — for example, having a diet soda when your stomach is empty — things are more regulated.

There’s still a lot more research to be done, but for now, know that the lower-calorie foods you eat that are artificially sweetened might not be helping you too much if you’re trying to burn as many cals as possible.

In general, it might be best to stick to all natural, non-processed foods if you’re worried about your diet. Everything in moderation, right?