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What Happens to Your Body When You Eat Artificial Sweeteners

Here's what doctors and dietitians have to say about artificial sweeteners.

So you've probably seen artificial sweeteners in your diet soda. You've also spotted them in your protein bars. And baked goods. And canned items. And many other "diet" or "sugar free" products. But despite brands universally including artificial sweeteners in many seemingly "healthy" foods, their safety and side effects are still up for debate.

How Do Artificial Sweeteners Work?

What are artificial sweeteners? "Artificial sweeteners, [also known as high-intensity sweeteners or sugar substitutes], are often sweeter than sugar but provide few, if any, calories," says Lynn Grieger, RDN, CDE, Everyday Health dietitian and diabetes educator.

Most artificial sweeteners "either are incompletely metabolized so they provide very few calories [known as 'nutritive sweeteners'], or aren't metabolized at all [known as 'non-nutritive sweeteners'], so they provide no calories," Grieger adds. The reason artificial sweeteners aren't metabolized by our bodies is "because our bodies don't have the enzymes needed to digest them," offers Oreoluwa Ogunyemi, MD, urologist and Health Coach.

Artificial sweeteners work by triggering the same sensory cells in our taste buds that send signals to our brain when we taste something sweet, like sugar, explains Grieger. And because artificial sweeteners are between 200 and 20,000 times sweeter than sugar, manufacturers can use so little in their formulation that they add almost no calories whereas the same amount of sweetness from sugar would have more calories.

RELATED: The science-backed way to curb your sweet tooth in 14 days.

Artificial Sweeteners List

The list of FDA-approved artificial sweeteners is lengthy and includes:

  • Acesulfame potassium (Ace-K)
  • Advantame
  • Aspartame
  • Neotame
  • Saccharin
  • Luo Han Guo fruit extracts
  • High-purity steviol glycosides (Stevia rebaudiana)
  • Sucralose

To make matters more complicated, the sweeteners often go by brand names like Nutrasweet, Sunett, Equal, Nectresse, Truvia, and Sweet'N Low. You can see a full list of artificial sweeteners and their brand names approved by the FDA here.

The Artificial Sweetener Side Effects You Should Know About

Unfortunately, some research shows these innocuous sounding sugar swap-ins can have a detrimental impact on your health. On the bright side, other research shows that artificial sweeteners don't create bad side effects in the consumer, especially if you're generally healthy in the first place. We tapped nutritionists and gastroenterologists to dive into the potential side effects of consuming artificial sweeteners. Read on to learn more about the potential side effects of artificial sweeteners — and be sure to share this story with all your Diet Coke-sipping friends.

Research about the potential side effects of artificial sweeteners are mixed, but if you're healthy, usage might be okay.

"Studies have suggested an association between the use of non-nutritive sweeteners and health outcomes (such as body weight, diabetes, cancer, and oral health). However, in a recent comprehensive systematic BMJ review, a broad range of health outcomes were investigated to determine a possible association with non-nutritive sweetener use in a generally healthy population," explains Farzaneh Daghigh, PhD from the Philadelphia College of Osteopathic Medicine. "There was no convincing evidence that non-nutritive sweeteners had any effect in adults on eating behavior, cancer, cardiovascular disease, kidney disease, mood, behavior or cognition. This study found a slight benefit in promoting weight loss and improving fasting blood glucose levels, but only in small studies and over short periods of time. Potential harms from the consumption of non-nutritive sweeteners could not be excluded."

Artificial sweeteners can impact your brain.

"When you consume artificial sweeteners some data suggests that artificial sweeteners cross the blood-brain barrier and disrupt hippocampal function. This impairs sensitivity to interceptive signals, dysregulate appetitive behavior, and thereby promote food intake," says Rocio Salas-Whalen, MD, endocrinologist and founder of New York Endocrinology.

Artificial sweeteners can retrain your taste buds.

And not necessarily for the better. "Because artificial sweeteners have many times the intensity of sweet flavor in comparison to natural sugars, you and your taste buds become accustomed to super sweet things," shares Tanya Freirich, MS, RD, CDN, CDE, nutritionist for Sweet Nova, an all-natural food company. "Those who consume artificial sweeteners may be become accustomed to ultra-sweet flavors. This may change their tastes and decrease their enjoyment of naturally sweet foods like fresh fruit as well as healthy foods that may be slightly bitter like whole grains or vegetables."

Artificial sweeteners may impact your gut health.

We'll file this one under "no, thank you: "Some studies have shown that [artificial sweeteners] affect the normal gut microbiota. This can lead to obesity and metabolic syndrome," notes Salas-Whalen, citing a 2014 study published in the respected journal Nature.

…which can lead to diabetes.

"Artificial sweeteners can alter your gut microbiota," says Freirich. "As per a recent study in Physiology & Behavior, the consumption of artificial sweeteners alters the gut microbiota and is linked with impaired glucose tolerance. Impaired glucose tolerance raises blood sugars and increases the risk for diabetes."

Artificial sweeteners simply love chilling in your gut.

"[The 2014 Nature study] showed that regular use of artificial sweeteners like saccharin, sucralose and aspartame, led to an abnormal mix of bacteria in the gut that increased risk of insulin insensitivity (the precursor of diabetes) and weight gain," explains Ogunyemi. "One way this may happen is that as the artificial sweetener sits in your gut and is not absorbed, it is used as 'food' for unhealthy bacteria, causing this to grow while the healthier critters are killed off."

And artificial sweeteners may be linked to a host of gastrointestinal issues.

"Another PLoS One study showed a similar effect of acesulfame potassium, but only in men," comments Ogunyemi (worth noting this study was conducted on mice, further research, especially on humans is needed to replicate the findings). "Gut dysbiosis, often associated with irritable bowel syndrome (IBS), is very common and not only leads to abdominal bloating and pain, but also decreases our ability to get the most nutrients from our food, decrease the health of our immune system and increase our risk of a host of chronic inflammatory disorders."

Beware that some artificial sweeteners have calories.

Artificial sweeteners can be non-nutritive or nutritive, although most artificial sweeteners fall under the non-nutritive umbrella. "Non-nutritive sweeteners are synthetic sugar substitutes that are free of calories and carbohydrates. They may be derived from naturally occurring plants or herbs and are many times sweeter than sugar," says Daghigh.

The other category of artificial sweetener is nutritive, which only includes aspartame. "The nutritive sweeteners may be lower in calories when compared to sugar and add caloric value to the foods that contain them," says Daghigh.

Artificial sweeteners can usher in overeating.

Ever notice how after you consume a diet soda with a meal, you eat more than you normally would or crave more food after your meal is completed? "While artificial sweeteners are supposed to help us reduce our calorie intake, the opposite may be true. Artificial sweeteners still trigger our sweet taste sensors, increasing insulin levels in the same way as if you eat sugar," notes Ogunyemi.

"This can lead to us to eat more calories than we would if we skipped the artificial sweetener and increases our risk of packing on the pounds around our midsection, which increases our risk for heart disease and heart attacks." See more on the connection between artificial sweeteners and obesity from a 2017 review in Current Gastroenterology Reports.

Aspartame isn't for all.

"Aspartame (NutraSweet or Equal) is approved for use in food as a nutritive sweetener. Aspartame contains calories, but because it is about 200 times sweeter than table sugar, consumers are likely to use much less of it," says Daghigh. "It loses its sweetness when heated, so it typically isn't used in baked goods. People with a rare congenital disease known as phenylketonuria (PKU) have a difficult time metabolizing phenylalanine, a component of aspartame, and should avoid aspartame." For more on specific sweeteners, read about every added sweetener ranked by nutrition!

Are Artificial Sweeteners Bad For You And Should You Avoid Them?

"The FDA regulates the safety of sugar substitutes with a goal of making sure that the amounts generally used are not harmful for the general population. FDA sets an Acceptable Daily Intake (ADI) for each type of sugar substitute which is the amount a person could consume daily over their lifetime without negative effects," explains Grieger.

"There are conflicting research studies, with some showing that artificial sweeteners increase sweet cravings and body weight, and others that artificial sweeteners have no effect," says Grieger. "I encourage each of my clients to limit both artificial sweeteners and sugars, and to be aware of any changes in their taste preferences and cravings so that they understand how these sweeteners affect them personally." Looking to cut down sweeteners — artificial or otherwise? Check out easy ways to stop eating so much sugar.

Perri O. Blumberg
Perri O. Blumberg is a freelance food, health, and lifestyle writer. Read more about Perri O.