As sugar has become the villain in our diets more people are choosing artificial sweeteners to avoid the “toxic” ingredient or help them achieve their weight loss goals.

But could these low to zero-calorie sweeteners like aspartame (also known as NutraSweet), Splenda and sucralose actually encourage weight gain?

Artificial sweeteners and your body weight

Artificial sweeteners have been promoted as a weight management tool to help overcome the obesity epidemic and reduce the risks of associated conditions such as type 2 diabetes, metabolic syndrome and heart disease. 

So does drinking artificial sweeteners help you lose weight and stay thin?

They may contain no-calories, but epidemiologic data suggest a positive link between the use of artificial sweeteners and weight gain. 

  • A two-year study of 166 school-aged children found the more diet soda they consumed, the greater the weight gain;
  • Observational studies of 3,682 adults over a 7-8 year period found those who drank diet soft drinks had consistently higher BMIs;
  • A study of nearly 1000 children found diet soda drinkers had a significantly elevated BMI and weight circumference.

While there is a lot of evidence to suggest artificial sweeteners may cause weight gain, there are some randomized controlled trials such as this study that has found substituting low-caloric options for table sugar may result in a modest weight loss.

But it’s not just about weight gain or loss. There is also new research showing artificial sweeteners can alter our gut microbiome inducing glucose intolerance. This highlights our gut bacteria may play a critical role in preventing the occurrence of obesity-related and sugar-driven conditions such as type 2 diabetes.

Controlling your sugar cravings with artificial sweeteners

Sugar is considered as addictive as illegal drugs and this may largely be due to the sweet taste stimulating the brain’s reward receptors and causing food cravings. In animal studies, given the chance, 94% of rats would choose sugar-water over cocaine-water!  

Sugar stimulates our brain’s reward centres through the activation of dopamine, our “feel-good” neurotransmitter. It also stimulates the release of our brain’s natural opioids just like heroin. 

So what if you swap sugar for artificial sweeteners? If you replace your regular soda with a calorie-free diet soda, will your sugar cravings subside?

Zero to low-calorie sweeteners are found to be much sweeter than sugar, however, they’re used only in tiny amounts. And those packets like Splenda typically have the same level of sweetness as table sugar.

Non-nutritive sweeteners such as saccharine, aspartame, acesulfame-K, sucralose, tagatose, and steviol glycoside are believed to replicate the very same cravings and addictive behaviours towards sweet foods as sugar. 

It’s those cravings that drive us to desire more sweet treats (from artificial or natural sweeteners) and may lead to weight gain after long-term consumption.

Low-calorie sweeteners and your overall food intake

To feel satisfied when eating, we require calories. While artificial sweeteners may hit the spot when it comes to our reward centres, some researchers believe being no-calorie, sweeteners may prevent us from feeling completely satisfied. This could lead you to consume more food and increase your overall calorie intake and in turn, gain weight. 

This, coupled with our desire for the sweet taste, may drive us to opt for less nutritious and more calorie-dense foods which will cause weight gain. 

It’s also believed, the extreme sweetness of artificial sugar substitutes may reduce our tolerance for naturally sweet foods. Dr David Ludwig, an obesity and weight-loss doctor at the American Boston Children’s Hospital, says people who frequently use artificial sweeteners may find naturally sweet foods, like fruit, and savoury options, like vegetables, unappealing and unpalatable.

Dr Ludwig’s other concern with the use of artificial sweeteners is that it may lead to us fooling ourselves into eating more food than otherwise necessary. We may fall into the trap of thinking: “I’m having stevia in my coffee, so it’s okay to have that biscuit” or “It’s diet Coke, so I can have three cans instead of one”. 

What’s the verdict?

There are mixed views on whether consuming artificial sweeteners will cause weight gain. However, the sugar cravings and dependancy combined with the potential for an increase in food consumption suggest you may have an uphill battle in preventing weight gain.

And if artificial sweeteners are used to encourage weight loss, the actual amount may not be all that significant. 

From an overall health point of view, you’ve also got to consider the intake of food products that contain artificial sweeteners. Most offer very little nutritional benefit if any at all.

For those who struggle with sweet cravings, blood sugar dysregulation or conditions like type 2 diabetes, you may want to consider avoiding artificial sweeteners and opting for a balanced, nutritious diet of low-sugar natural foods instead.