A review of recent European research found no evidence that non-sugar sweeteners negatively affect weight management or several health markers.
Researchers also found no evidence that consuming sweeteners or sweet-tasting foods changes people's preferences for sweet foods.
The findings offer reassurance about sugar substitutes, but they don't mean every sweetener has the same effects or that more research isn't needed.
Sugar substitutes are found in many everyday foods and drinks, from diet beverages to sugar-free snacks. Known as non-nutritive sweeteners (NNSs), these ingredients provide a sweet taste with little to no energy, making them an option for people looking to reduce their sugar intake.
But questions remain about whether these sweeteners affect weight, metabolic health, or our desire for sweet foods. Some health recommendations have advised against relying on them for weight control, while other professional groups consider them a useful way to cut back on sugar.
A new review published in Nutrients examines evidence from three major European research projects to better understand how these sweeteners may affect health and eating habits.
“The findings from all three major European consortia point in the same direction and add important weight to the broader evidence on non-nutritive sweeteners and sweet taste,” researcher Eva Marija Cad said in a news release.
“Collectively, they suggest that we can reduce sugar intake while retaining sweetness and the enjoyment it brings in our diets.”
How did researchers study sweeteners?
Researchers reviewed findings from three European research consortia: SWEET, SWITCH, and Sweet Tooth. Rather than conducting a single new experiment, the team brought together results from randomized controlled trials, which are designed to help researchers understand whether an intervention directly causes a particular outcome.
The studies included short-term and longer-term research examining the effects of non-nutritive sweeteners and different levels of dietary sweetness.
Researchers looked at several outcomes, including body weight, body composition, blood sugar regulation, cholesterol, blood pressure, liver health, gut bacteria, and preferences for sweet foods.
Some studies examined what happened when people replaced sugar with non-nutritive sweeteners, while others explored whether changing how much sweetness people consumed affected their health or eating behavior.
What did the review find, and what does it mean for consumers?
Across the studies, researchers found no evidence that non-nutritive sweeteners or higher dietary sweetness negatively affected body weight, health markers, or preferences for sweet foods.
In one yearlong SWEET study, participants who included sweeteners in their diets maintained somewhat greater weight loss than those who avoided them. A separate 52-week SWITCH trial found slightly greater weight loss among people drinking sweetened beverages than those drinking water, although the difference was not considered clinically meaningful.
Researchers also found no consistent negative effects on blood sugar, insulin, blood pressure, cholesterol, liver enzymes, or appetite. One study identified a modest change in gut bacteria, but it was not accompanied by worsening heart or metabolic health markers.
The review also found no evidence that sweeteners make people crave more sweetness or eat more overall.
However, the findings have limitations. Many participants were overweight adults, and some studies took place in structured weight-management programs. The researchers also noted that longer-term effects and effects in children and teenagers remain unclear.
“A common concern is that replacing sugar with non-nutritive sweeteners might lead to a stronger preference for sugary sweet foods or stimulate appetite,” researcher Graham Finlayson said in the release. “Across these controlled studies, that prediction was not supported.
“Sweeteners are not a weight-management strategy by themselves, but they can provide a useful way to reduce sugar while retaining sweetness within a broader healthy diet.”