Review Synthesizes European Trials on Non-Nutritive Sweeteners on Weight, Health, and Taste Outcomes

A narrative review published in Nutrients pulls together findings from three large European research consortia—SWEET, SWITCH, and Sweet Tooth—to examine how non-nutritive sweeteners (NNSs) and dietary sweet taste exposure relate to body weight, cardiometabolic biomarkers, and sweet taste preference.¹ The review was developed alongside a 2025 webinar series hosted by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) and was led by Eva Marija Čad of the University of Ljubljana and Wageningen University & Research.^1,2

“Overall, the reviewed evidence suggests that replacing sugar intake with NNSs may support weight management strategies, while differences in habitual dietary sweet taste exposure per se appear largely neutral with respect to health-related biomarkers and sweet taste preferences,” the study authors ultimately concluded.

How Was the Review Conducted?

The authors synthesized data from randomized controlled trials (RCTs) run within three multi-year consortia.

• The SWEET consortium contributed a one-year weight loss maintenance trial following an initial two-month weight loss phase, a two-week crossover trial testing biscuits sweetened with neotame or steviol glycoside rebaudioside M against sucrose, and an acute crossover beverage trial comparing NNS blends with sucrose before a carbohydrate-rich meal.
• The SWITCH consortium ran a 52-week parallel-group trial comparing NNS-sweetened beverages with water within a structured behavioral weight management program.
• The Sweet Tooth consortium assigned participants to low, regular, or high dietary sweetness exposure for six months, independent of any weight loss goal, followed by four months of follow-up.

Outcomes assessed across the trials included body weight and composition, glucoregulatory and endocrine markers, cardiometabolic risk factors, gut microbiota, liver enzymes, sweet taste liking, appetite, and food intake.

What Did the Trials Find?

In the SWEET maintenance trial, both groups sustained substantial weight loss at 12 months, with NNS-inclusion yielding about 1.6 kg more loss than avoidance and no difference in adiposity. SWITCH showed comparable weight loss at 12 weeks, with a numerically greater but not clinically significant reduction in the NNS group by week 52. Sweet Tooth found no effect of sweetness exposure on weight or composition.

What Are the Limitations?

The authors note that trial populations were largely limited to European adults with overweight or obesity, often within structured intervention settings, which may limit generalizability to other groups or real-world dietary patterns. Several biomarker and behavioral outcomes were secondary or exploratory, and some analyses may have been underpowered. Higher-than-expected dropout in places and potential underreporting of dietary intake were also flagged. The authors caution that null findings indicate an absence of detectable differences within the populations and timeframes studied, not proof of no effect. Additionally, long-term and pediatric effects remain uncertain.

What Are the Main Takeaways for Sweeteners?

Commenting on the review, lead author Eva Marija Čad commented on the potential role of sweeteners in diets. “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,” Čad stated. “Collectively, they suggest that we can reduce sugar intake while retaining sweetness and the enjoyment it brings in our diets.”

Co-author Graham Finlayson of the University of Leeds addressed concerns about NNSs affecting preferences or appetite. “A common concern is that replacing sugar with non-nutritive sweeteners might lead to a stronger preference for sugary sweet foods or stimulate appetite,” Finlayson stated. “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.”

References

1. Čad EM, Appleton KM, Blaak EE, et al. Effects of non-nutritive sweeteners and sweet taste exposure on weight management, biomarkers of health and sweet taste preference—a review of the evidence from recent European consortia studies. Nutrients. 2026;18(11):1647. doi:10.3390/nu18111647
2. Institute for the Advancement of Food and Nutrition Sciences. No evidence that sugar substitutes harm weight, health, or sweet taste preferences. Newswise. September 8, 2026. Accessed September 15, 2026. https://www.newswise.com/articles/no-evidence-that-sugar-substitutes-harm-weight-health-or-sweet-taste-preferences