Benefits in weight management

Replacing sugar-sweetened foods and beverages with options sweetened with low/no calorie sweeteners can help reduce overall daily sugar intake. When used as part of a balanced diet and healthy lifestyle, this substitution can contribute to a lower total energy (calorie) intake and, in turn, serve as a useful tool in managing excess body weight.¹

Given the persistently high global prevalence of overweight and obesity, alongside public health recommendations to reduce sugar intake in both adults and children, low/no calorie sweeteners may play a supportive role in achieving these goals.²

The science behind low/no calorie sweeteners and weight management

Evidence from systematic reviews and meta-analyses of randomised controlled trials (RCTs) supports a role for low/no calorie sweeteners in weight management. These studies consistently show that replacing sugar with sweeteners can help reduce overall energy intake and, in turn, contribute to modest weight loss over time. ^3-10

RCTs are considered the gold standard for assessing cause-and-effect relationships in nutrition research. The consistency of findings across multiple short- and long-term RCTs, supporting sweeteners’ helpful role in weight control, strengthens the evidence base. Notably, recent large, long-term trials have further reinforced low/no calorie sweeteners’ potential role in longer-term weight loss maintenance.^11,12

Findings from these long-term studies indicate that incorporating low/no calorie sweeteners in sugar-reduced diets can assist in sustaining weight loss over time. Proposed mechanisms include reduction in energy intake and improved adherence to a healthy eating plan, potentially through less cravings and greater diet satisfaction.¹² Long-term weight maintenance remains one of the greatest challenges in weight management, making these findings clinically relevant.

Of course, low/no calorie sweeteners are no magic bullet and cannot make us lose weight on their own. Scientific experts explain that their benefit depends on the extent to which sweeteners replace caloric sugars and on the overall quality of the dietary pattern in which they are used.^1,2

ASSOCIATIONS BETWEEN Low/no calorie sweetener INTAKE and obesity

Contrary to findings from RCTs, evidence from observational epidemiological studies is less consistent, contributing to ongoing debate and conflicting recommendations regarding low/no calorie sweeteners’ use.¹³

However, a recent umbrella review highlighted important methodological limitations and divide in analyses of observational studies.¹⁴ “Naïve” analyses of prospective cohort studies that do not adjust for key confounders or for the intended substitution of sugar with sweeteners have frequently reported positive associations between low/no calorie sweeteners’ consumption and higher obesity risk. However, these studies often rely on a single baseline dietary assessment and cannot account for changes in diet over time. In contrast, bias-adjusted models and substitution analyses that account for energy replacement and changes in intake over time report different outcomes. In these bias-adjusted analyses, the findings are generally aligned with those observed in clinical trials: substitution of sugars with low/no calorie sweeteners is associated with lower body weight and reduced obesity risk.¹⁴

It is also important to recognise that observational studies are inherently more susceptible to residual confounding and reverse causality. Individuals with overweight or obesity may be more likely to consume low/no calorie sweeteners as part of weight management efforts, which can result in positive associations in prospective analyses with single baseline dietary assessments. Therefore, observed associations between sweeteners’ intake and obesity should be interpreted cautiously and within the broader context of the totality of evidence.¹⁵

RECOMMENDATIONS ABOUT Low/no calorie sweetener USE IN WEIGHT CONTROL

Inconsistencies between findings from RCTs and observational studies have contributed to variation in recommendations from health organisations, which may lead to uncertainty among healthcare professionals and the public.

In May 2023, the World Health Organization (WHO) issued a guideline including a conditional (weak) recommendation that sweeteners should “not be used as a means of achieving weight control or reducing the risk of noncommunicable diseases” (WHO, 2023).¹⁶ This guideline placed substantial weight on findings from observational studies with single baseline dietary assessment in which positive associations between low/no calorie sweeteners’ intake and obesity outcomes have been reported. The interpretation of this evidence differs from analyses that give greater emphasis to RCTs and bias-adjusted prospective cohort studies.¹³

In contrast, in 2025 the Scientific Advisory Committee on Nutrition (SACN) in the United Kingdom concluded that evidence from both short- and long- term RCTs consistently shows that, compared with free sugars, low/no calorie sweeteners reduce energy intake.¹⁷ SACN stated that replacing sugars with sweeteners may help reduce sugar and energy intake from foods and drinks, which in turn, can help with weight management at least in the short term, placing greater weight on RCTs as these minimise bias and confounding.

Several professional organisations similarly recognise a potential role for low/no calorie sweeteners in supporting weight and diabetes management strategies, when used as part of an overall healthy diet. This position is reflected in a joint statement from the British Dietetic Association (BDA), the British Nutrition Foundation (BNF), and Diabetes UK,¹⁸ and aligns with guidance from the American Diabetes Association (ADA)¹⁹ and the Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD).²⁰ In Brazil, similar positions have been issued recently by three organisations, the Association of Nutrology (Associação Brasileira de Nutrologia – ABRAN), the National Association for Diabetes Care (Associação Nacional de Atenção ao Diabetes – ANAD), and the Brazilian Society of Food and Nutrition (Sociedade Brasileira de Alimentação e Nutrição – SBAN).²¹

In the context of rising global obesity prevalence, identifying evidence-based strategies to reduce excess energy intake remains a public health priority. Current evidence from RCTs and appropriately adjusted prospective cohort studies does not demonstrate that low/no calorie sweeteners contribute to weight gain. In contrast, low/no calorie sweeteners may represent one option to support reductions in sugars and energy intake.

Low/no calorie sweeteners, appetite and sweetness preference

Low/no calorie sweeteners may help satisfy a desire for sweet taste with few/ no calories.²² One study, for example, found that consuming low/no calorie sweetened drinks may help some individuals to control food cravings, reduce the desire to consume sweet foods, and decrease their actual consumption, while contributing to greater meal enjoyment.²³ Importantly, current evidence does not indicate that consumption of low/no calorie sweeteners can increase appetite or liking for sweet taste.^1,22,24

 Systematic reviews examining dietary sweetness exposure report no consistent evidence that a higher exposure to sweet taste per se, from both sweeteners or sugars, meaningfully alters sweet taste preferences, food selection, or total energy intake over time.^24,25 Longer-term clinical intervention studies similarly indicate that reducing or increasing exposure to sweet tasting foods does not result in systematic changes in liking for sweet taste.^26,27

Evidence from short term RCTs shows that acute exposure to sweet taste is often followed by a short-term decrease in the desire for sweet foods. This effect is consistent with sensory-specific satiety, a well-established phenomenon whereby the pleasantness and liking of foods decline more for items sharing the same sensory characteristics as those recently consumed.²⁵  

Evidence from longer-term clinical trials further supports these findings. A recently published, large RCT reported that altering dietary exposure to sweet-tasting foods for 6 months did not significantly affect sweet taste perception and preference, food choice, energy intake, or body weight.²⁶ Following the intervention, participants’ sweet food consumption naturally returned to their baseline sweet food intake within the follow-up period, suggesting no lasting behavioural modification. Preliminary findings from a related long-term study conducted by the Monell Center and the USDA²⁷ are consistent with these observations, and in agreement with earlier studies by the same research center.²⁸

Overall, the available evidence does not support the hypothesis that exposure to low/no calorie sweeteners increases appetite or preference for sweetness or promotes greater food and energy intake. When used to replace sugar within an overall structured dietary pattern, low/no calorie sweeteners may help satisfy the desire for sweet taste while limiting sugar and energy intake, which may support adherence to a sugar-reduced, healthy diet in weight management efforts.