Guidance on low/no calorie sweeteners (LNCS) has diverged in recent years, creating uncertainty for healthcare professionals advising patients on their use. Despite differing recommendations from health-related organisations, there is broad agreement on one critical point: more robust, large, long-term randomised controlled trials (RCTs) are needed to determine whether prolonged LNCS use can support weight and diabetes management without adverse health effects. In this blog, we review three new landmark trials designed to address this evidence gap and provide new insight into the health effects and benefits of LNCS.
Vicky Pyrogianni, MSc, Dietitian – Nutritionist, Nutrition Science Director, International Sweeteners Association (ISA)
Navigating divergent recommendations on low/no calorie sweeteners
In 2023, the World Health Organization (WHO) issued a conditional (i.e. weak) recommendation suggesting against the use of non-sugar sweeteners for weight control.1 Two years later, the UK Scientific Advisory Committee on Nutrition (SACN) concluded that replacing sugars with LNCS may help reduce sugar and energy intake from foods and drinks, at least in the short term.2 More recently, a joint position statement from the British Dietetic Association (BDA), the British Nutrition Foundation (BNF), and Diabetes UK stated that LNCS can play a role in supporting weight control and diabetes management strategies, although not as a stand-alone solution.3 This aligns with guidance from the American Diabetes Association (ADA)4 and the Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD)5. So, why do recommendations differ so markedly?
Divergent guidance largely reflects differences in how organisations evaluate and weight the available evidence, or how evidence is interpreted when forming recommendations.6 For example, the WHO guideline prioritised longer-term observational studies over evidence from RCTs, while SACN gave greater weight to good quality RCTs, where available, because these minimise the potential for bias and confounding.2 Furthermore, the prospective cohort studies underpinning the WHO conclusions relied on single baseline exposure assessments, which do not adequately reflect the intended use of LNCS as sugar substitutes. This is a critical point, as it is well established that LNCS do not directly support weight management and glycaemic control; rather, they can serve as useful adjuncts to facilitate dietary changes to reduce sugar and energy intake.
In its guideline, the WHO noted that “the small amount of weight loss resulting from non-sugar sweeteners use in short-term experimental settings may not be relevant to the effects of long-term NSS use in the general population”, arguing that existing RCTs are not long enough to determine the impact on weight loss. Since then, however, new evidence from three major RCTs has emerged, directly addressing these identified gaps. Collectively, these trials provide longer-term data suggesting that LNCS use may support weight loss maintenance and help people living with obesity and/or diabetes manage their body weight over extended periods. 7-9
1. Low/no calorie sweeteners in long-term weight management: The EU SWEET project
A multicentre trial that was part of the EU Horizon 2020 funded SWEET project is among the largest and longest RCTs to date examining the impact of LNCS on weight-loss maintenance in adults with overweight or obesity.7 In this year-long trial, 341 adults first completed an eight-week low-energy diet achieving an average weight loss of approximately 10 kg before entering a ten-month weight-maintenance phase. During the maintenance period, participants were randomised to an LNCS group, where sugar-rich foods and beverages were replaced with foods and drinks containing LNCS (e.g., aspartame, sucralose, stevia) as part of a healthy, low-sugar diet, or to a control group instructed to follow a similar low-sugar diet without sweeteners.
After 12 months, both groups maintained a substantial proportion of their initial weight loss. However, the LNCS group maintained more weight loss (7.2 kg) than those in the control group (5.6 kg), representing a difference of 1.6 kg in favour of LNCS use. Among participants with the highest dietary compliance, the difference increased to 3.8 kg in favour of sweetener use. The LNCS group also reduced sugar intake by approximately twice as much as the control group, confirming that LNCS were used as intended, i.e., as sugar replacements rather than additional sweeteners.
Pang and colleagues suggested that the superior weight-loss maintenance with LNCS use may be partly explained by higher diet satisfaction and lower cravings in the sweetener group, as well as beneficial changes in gut microbiota composition. Subgroup analyses showed distinct beneficial shifts in gut microbial composition among LNCS users, including greater abundance of short-chain fatty acid–producing taxa linked to improved metabolic regulation, without signs of dysbiosis. Importantly, no significant group differences were observed in diabetes-related outcomes (glucose, insulin, HbA1c) or cardiovascular risk markers at 12 months, indicating no cardiometabolic harm from prolonged LNCS use.
2. LNCS beverage consumption in people with type 2 diabetes: The SODAS Trial
The Study of Drinks with Artificial Sweeteners (SODAS), a 6-month RCT in 181 adults living with type 2 diabetes, examined whether replacing habitual low/no calorie sweetened beverages with plain water would improve patients’ glycaemic control.8 Adults with well-controlled type 2 diabetes (HbA1c 6.5–8.5%) who regularly consumed LNCS beverages were randomised to either continue consuming commercial LNCS beverages of their choice, or to replace these with unflavored bottled or sparkling water.
Contrary to expectations, glycaemic control assessed with HbA1c improved in the group that continued consuming LNCS beverages, while HbA1c increased in the water group over the 24-week intervention. The mean between-group difference in HbA1c change was 0.29% higher in the water arm. Secondary metabolic measures, including fructosamine, fasting glucose and insulin, continuous glucose monitoring metrics, did not differ significantly between groups. Body weight decreased slightly in the LNCS beverage arm and remained stable in the water group.
Overall, the findings of the study by Odegaard et al. suggest that continued consumption of LNCS beverages in habitual consumers of diet drinks was associated with modest advantages in body weight and slightly improved glycaemic control in adults with type 2 diabetes.
3. Does sweet taste exposure change preferences? The Sweet Tooth Trial
Prevailing public health messaging often suggests that high exposure to sweet tastes drives a “sweet tooth,” increasing sweet preferences, calorie intake, and risk of weight gain. The Sweet Tooth trial tested this hypothesis in 180 healthy adults via a rigorous 6-month parallel RCT with a 4-month follow-up period.9 Participants were randomised to diets varying in sweetness exposure:
- Low sweet exposure(minimizing sweet foods/beverages)
- Regular exposure(typical dietary pattern)
- High exposure(increased sweetness from both sugars and LNCS)
Despite large differences in dietary sweetness, preference for sweet taste remained stable across all groups. There were no meaningful changes in how intensely participants perceived sweetness or how much they liked sweet foods. Group differences did not appear in calorie intake, food choices, body weight, or metabolic biomarkers. Notably, participants tended to return to their baseline patterns of sweet food consumption after the intervention concluded.
Practical takeaways for dietitians and nutritionists
Taken together, these trials support a nuanced, evidence-informed approach to the use of LNCS, reinforcing the importance of patient-centred dietary care rather than one-size-fits-all recommendations.
- Context of use matters
LNCS are not a magic bullet solution on their own as they do not exert pharmacological weight-loss effects. They appear most beneficial when used as replacements for sugars within an overall low-sugar, energy-controlled dietary pattern. When applied in this way, LNCS can support weight-loss maintenance without adverse cardiometabolic effects.
- Individualised guidance
For individuals with type 2 diabetes who already consume LNCS, continuing the use of low-calorie sweetened beverages may be a reasonable option, particularly when it aligns with personal preferences and supports adherence to a healthy diet.
- Set realistic expectations about sweet taste preferences
Sweet taste preferences in adults are relatively stable and not easily altered by increasing or decreasing dietary sweetness exposure. For dietitians, this suggests that strategies aimed solely at reducing sweetness are unlikely to meaningfully shift preferences or reduce energy intake. Instead, interventions should prioritise overall dietary quality, energy balance, behavioural strategies, and sustainable habit change.
References:
- World Health Organization. Use of non-sugar sweeteners. WHO guideline. Geneva, Switzerland: World Health Organization; 2023. https://www.who.int/publications/i/item/9789240073616.
- Scientific Advisory Committee on Nutrition (SACN). SACN statement on the WHO guideline on non-sugar sweeteners: summary. Office for Health Improvement and Disparities; April 2, 2025. https://www.gov.uk/government/publications/sacn-statement-on-the-who-guideline-on-non-sugar-sweeteners/sacn-statement-on-the-who-guideline-on-non-sugar-sweeteners-summary. Accessed February 5, 2026.
- British Dietetic Association (BDA); British Nutrition Foundation (BNF); Diabetes UK. Joint position statement on the use of low or no calorie sweeteners (LNCS). October 2025. https://www.bda.uk.com/resource-report/joint-position-statement-on-the-use-of-low-or-no-calorie-sweeteners-lncs.html. Accessed February 5, 2026.
- American Diabetes Association Professional Practice Committee for Diabetes* . 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2026. Diabetes Care. 2026;49(Supplement_1):S89-S131. doi:10.2337/dc26-S005
- Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD). Evidence-based European recommendations for the dietary management of diabetes. Diabetologia. 2023;66(6):965-985. doi:10.1007/s00125-023-05894-8
- Ayoub-Charette S, Kavanagh M, Khan T, Sievenpiper J. Reconciling conflicting evidence on low- and no-calorie sweeteners and cardiometabolic outcomes: an umbrella review using naïve and bias-adjusted methods. Appl Physiol Nutr Metab. 2025;50:1-26. doi:10.1139/apnm-2025-0068
- Pang MD, Kjølbæk L, Bastings JJAJ, et al. Effect of sweeteners and sweetness enhancers on weight management and gut microbiota composition in individuals with overweight or obesity: the SWEET study. Nat Metab. 2025;7(10):2083-2098. doi:10.1038/s42255-025-01381-z
- Odegaard AO, Chang J, Jiang L, et al. The Effect of Substituting Water for Artificially Sweetened Beverages on Glycemic and Weight Measures in People With Type 2 Diabetes: The Study of Drinks With Artificial Sweeteners (SODAS), a Randomized Trial. Diabetes Care. 2026;49(2):239-246. doi:10.2337/dc25-1516
- Čad EM, Mars M, Pretorius L, et al. The Sweet Tooth Trial: A Parallel Randomized Controlled Trial Investigating the Effects of A 6-Month Low, Regular, or High Dietary Sweet Taste Exposure on Sweet Taste Liking, and Various Outcomes Related to Food Intake and Weight Status. Am J Clin Nutr. 2026;123(1):101073. doi:10.1016/j.ajcnut.2025.09.041
Disclaimer: This blog was supported by an unrestricted educational grant from the healthcare professional support team at the International Sweeteners Association. Approval of each partnered activity is carefully assessed for suitability on a case by case basis and is independently peer reviewed Any financial support from grants does not imply any endorsement of an organisation or brand by MyNutriWeb, its organisers, its moderators or any participating healthcare professional, or their association. Funds are reinvested into the creation and promotion of professional development opportunities on MyNutriWeb.
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