Sugar substitutes fail to fuel sweet cravings or weight gain across yearlong trials

A recent analysis of three large European studies spanning several years has found that non-nutritive sweeteners (NNSs) and increased sweetness in the diet do not lead to weight gain, adverse metabolic effects or heightened sweet cravings among overweight adults.

Research led by Eva Marija Čad of the University of Ljubljana and Wageningen University & Research, alongside colleagues from the University of Leeds and other European institutions, reviewed data from the SWEET, SWITCH and Sweet Tooth trials. These projects aimed to assess whether substituting sugar with NNSs impacts weight, cardiovascular health and taste preferences over extended periods.

Across all studies, the authors observed no negative effects on weight loss or maintenance when NNSs replaced sugar. In fact, one trial indicated that participants who consumed NNSs maintained slightly more weight loss after a year compared to those avoiding them. However, the differences were minimal and not clinically significant.

Blood sugar, insulin, blood pressure, cholesterol and liver enzyme levels remained stable regardless of whether participants consumed NNSs or not. Some short-term studies noted smaller post-meal blood sugar spikes when using sweeteners, but no detrimental effects on cardiometabolic risk markers were observed.

Moreover, the studies did not support the notion that consuming sweeteners or a sweeter diet trains individuals to crave more sweetness or eat more overall. In a weight-maintenance trial, those avoiding sweeteners actually developed a stronger preference for sweet foods over time, while those using sweeteners did not.

Despite the reassuring findings, the authors caution that the studies were conducted mainly in overweight adults within structured programs, which may limit generalizability to other populations. Some outcomes were secondary or exploratory, and dropout rates were higher than ideal. Additionally, self-reported dietary intake can be unreliable.

The researchers emphasize that the lack of detected differences in their analyses does not prove the absence of effects under any circumstances, only a lack of detectable differences within the specific populations and timeframes examined. Long-term effects and the impact on children and adolescents remain unclear.

Overall, the findings suggest that NNSs can aid in weight management and allow individuals to maintain sweetness in their diets without harming metabolic health. However, NNSs should not be seen as a standalone solution for weight management, and a broader healthy diet remains essential.