New Evidence That Artificial Sweeteners Are Linked with Weight Gain


New Evidence That Artificial Sweeteners Are Linked with Weight Gain

There’s mounting evidence that sugar is linked with weight gain as well as other health problems. No wonder, people are making the switch to artificial sweeteners. You’re probably familiar with sweeteners that come in pink, yellow, and blue packets and boast no calories. Currently, six synthetic sweeteners have been approved for use in the United States. These include saccharin, aspartame, advantame, sucralose, neotame, and acesulfame potassium. These sweeteners are hundreds of times sweeter than the old stand-by, sugar. One of the more popular of these sweeteners is sucralose, sold under the brand name Splenda. You probably recognize it in bright, yellow packs at restaurants.

Why are these sweeteners so popular? A single serving of these sweeteners contains no calories. In fact, they aren’t even completely absorbed by your body. However, that doesn’t mean they have no impact on your health. In fact, research now shows that artificial sweeteners can alter the bacteria that lie in your gut. With so much focus on probiotics as a means of improving gut and immune health, we know that a healthy composition of “good” bacteria in the gut is essential for health. However, artificial sweeteners seem to alter gut bacteria in an unfavorable way. What’s more, in mouse studies, these sweeteners change these gut residents in a way that fuels metabolic problems and, potentially, weight gain.

Artificial Sweeteners and Insulin Sensitivity

In a mouse study, mice that consumed artificial sweeteners on a daily basis experienced sharp rises in blood sugar and became less insulin sensitive. When they gave the mice oral antibiotics, these changes gradually reversed, suggesting that alterations of gut bacteria likely contributed to the poor glucose control. The artificial sweeteners they used in the study were saccharin, sucralose, and aspartame.

More Evidence Linking Artificial Sweeteners to Weight Gain

Now a new study finds another reason to cut back on artificial sweeteners. In this study, researchers subjected human stem cells derived from fat tissue to sucralose. The amount they used was equivalent to what a human would take in by drinking four cans of diet soda daily. Even as an adult, you have a stash of stem cells capable of forming new fat cells and they await the opportunity to morph into full-blown fat cells. In the presence of sucralose, new fat droplets formed within these stem cells. Plus, exposure to sucralose also activated inflammatory genes as well as those that code for the synthesis of new fat.

To further explore this link, researchers took biopsies of abdominal fat from overweight and normal-weight individuals who consumed artificial sweeteners. When they compared the samples to adults who didn’t consume artificial sweeteners, they found important differences. For one, participants who consumed artificial sweeteners showed an increase in genes involved in fat synthesis. Secondly, the cells of participants that used artificial sweeteners took up glucose more rapidly. The researchers believe that both of these findings could drive glucose intolerance and gains in body fat.

Do Artificial Sweeteners Impact Appetite?

Another concern is that artificial sweeteners may disrupt the link between sweetness and calories. If you eat something that tastes sweet, your body expects calories to follow. When they don’t, the desire to eat isn’t satiated. You continue to crave the taste of sweet and your taste buds and brain are unfulfilled. Plus, some studies show that artificial sweeteners don’t activate the dopamine reward centers in the brain the same way sugar does. So, you don’t get the positive reinforcement and sense of satisfaction that eating something naturally sweet provides. When you eat a cookie sweetened with an artificial sweetener, you may not get the same sense of satisfaction that you would from a naturally sweetened cookie and, therefore, eat more.

So, artificial sweeteners may increase weight gain in three ways:

·       By altering gut bacteria to forms that predispose to insulin resistance

·       By increasing glucose uptake by fat cells & activating genes involved in fat synthesis & storage

·       By not satisfying sweet cravings in the same way sugar does and by the mismatch between sugar and calories.

The Bottom Line

Artificial sweeteners might seem like a way to “cheat” and get a taste of sweet without the calories, these sweeteners may still contribute to weight gain despite their lack of calories. A better approach is to gradually wean your taste buds off sugar AND artificial sweeteners. Slowly decrease the quantity of all the sweeteners that you use. If, on occasion, you need a little sweetener for a cup of coffee or tea, consider a natural alternative, like Stevia, another zero-calorie sweetener alternative.

How safe is Stevia? One study showed that large amounts of Stevia were linked with infertility in rats. However, there’s no evidence that Stevia is harmful in moderate quantities in humans. In fact, some research shows Stevia lowers blood pressure and blood sugar. In addition, Stevia has been used as a sweetener in Japan for more than 30 years without problems.

Another natural, zero-calorie sweetener gaining favor is monk fruit. The mogrosides in monk fruit have antioxidant and anti-inflammatory properties and may have other health benefits. However, monk fruit has still not been well studied in humans, although humans have eaten monk fruit for many years without ill effects. Again, moderation is key. You shouldn’t overconsume any type of sweetener, artificial or natural. The take-home message? There’s not “free lunch” when it comes to sweeteners. It’s best to cut back on all of them. Yet, natural, no-calorie sweeteners may be a better choice if you can’t give up the taste of sweet entirely.



Medical News Today. “Low-Calorie Sweeteners Increase Fat Formation, Study Finds”
Am J Clin Nutr. 2013 Mar;97(3):517-23. doi: 10.3945/ajcn.112.050997. Epub 2013 Jan 30.
Harvard T.H. Chan School of Public Health. “Artificial Sweeteners”
Eur J Clin Nutr. 2007 Jun;61(6):691-700. Epub 2007 Feb 7.
Authority Nutrition. “Monk Fruit Sweetener – Good or Bad?”
Food and Chemical Toxicology. Volume 46, Issue 7, Supplement, July 2008, Pages S40–S46.
Phytotherapy Research. Volume 20, Issue 9. September 2006 Pages 732–736.
Appetite. 2010 Aug; 55(1): 37–43.


Related Articles By Cathe:

Are Artificial Sweeteners Safe or Not?

Do Artificial Sweeteners Cause Weight Gain?

What Does Sugar-Free Really Mean?


Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos, DVDs and Free Weekly Newsletter. Here are several ways you can watch and work out to my exercise videos and purchase my fitness products:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy