Sweeteners 'can help weight management' Leeds psychology research finds

Artificial sweeteners can help people maintain weight-loss without any apparent risks to their wider health, according to a newly published research review co-authored by Leeds academics.

The narrative review, published in peer-reviewed journal Nutrients, was co-written by Professors Graham Finlayson and Jason Halford (Psychology), and looked at the results of three large European research consortia – SWITCH and SWEET, both of which had significant work packages conducted at University of Leeds, and Sweet Tooth.

The new paper addresses longstanding questions about non-nutritive sweeteners (NNSs) and their affect on body weight, metabolic health, and people's taste preferences over time. It shows the studies do not support concerns that replacing sugar with low- and no-calorie sweeteners could increase cravings for sweet foods or stimulate appetite.

Professor Finlayson, who leads the Appetite and Obesity Research group at Leeds, said: “A common concern is that replacing sugar with non-nutritive sweeteners might lead to a stronger preference for sugary sweet foods or stimulate appetite. 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.” 

To compile the narrative review, the authors focused specifically on evidence from the three large European multi-year, multi-centre randomized trials designed to isolate cause-and-effect relationships under real-world conditions.

What the trials found

• Replacing sugar with non-nutritive sweeteners did not undermine weight loss or maintenance – and in some cases appeared to help. In a one-year weight-loss-maintenance trial from SWEET, people who included NNSs in their diet maintained modestly greater weight loss after a year than those who avoided them.
• Blood sugar, insulin, blood pressure, cholesterol, liver enzymes, and related biomarkers were generally stable and comparable across sweetener and non-sweetener groups.
• No evidence that consuming sweeteners — or a sweeter diet generally — trains people to crave sweetness or eat more. In the SWEET weight-maintenance trial, people who avoided sweeteners actually developed a stronger liking for sweet foods over time.

The narrative review work was led by Dr Eva Marija Čad of the University of Ljubljana and Wageningen University. She said: “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.

“Collectively, they suggest that we can reduce sugar intake while retaining sweetness and the enjoyment it brings in our diets.”

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

The authors note important limits to the evidence. The trials were conducted mainly in overweight adults, often within structured behavioural or clinical programs, so results may not generalize to other populations or everyday eating patterns. Long-term effects, and effects in children and adolescents, remain unclear.

Building on these findings, Dr Catherine Gibbons with Graham Finlayson and Jason Halford will begin a new PhD project this autumn to investigate more closely the behavioural and psychological mechanisms through which sweeteners and exposure to sweet taste may influence appetite, weight management and health.

The project will draw on detailed data collected within the SWITCH and SWEET programmes and related research to explore why low- and no-calorie sweeteners may help some people adhere to weight-management diets and whether these effects can be explained by changes in appetite, cravings, food reward and diet satisfaction.

Further information

• "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" was published Nutrients on May 22, 2026. DOI: 10.3390/nu18111647
• The review of the European evidence was supported by Institute for the Advancement of Food and Nutrition Sciences’ Low- and No-Calorie Sweeteners Committee.
• SWEET, SWITCH, and Sweet Tooth studies were funded respectively by the EU's Horizon 2020 program, the American Beverage Association, and the Dutch government's TKI Top Sector Agri-Food public-private partnership scheme, with private-sector contributions.
• Read more about the SWEET project and its findings