In the news: should we avoid using non-sugar sweeteners for weight loss?Last Updated : 22 May 2023
Sweeteners are used in foods to replace sugar and add a sweet taste without (or with very few) calories, are therefore often used by people trying to lose or maintain their weight. However, recent news stories warned against the use of sweeteners, for weight loss. Here are a few things to keep in mind when reading the headlines.
The study behind the headlines
The report behind the news was released by the World Health Organization (WHO).1 The WHO carried out a systematic review and meta-analyses looking at all the available scientific evidence on the use of non-sugar sweeteners and their long-term health effects. They recommend against the use of non-sugar sweeteners to control body weight or to reduce the risk of non-communicable diseases (NCDs), such as type 2 diabetes and cardiovascular diseases (CVDs).
The recommendation refers to both artificial sweeteners (such as aspartame, saccharin, sucralose etc.) and plant-based ones (such as stevia), but not sugar alcohols (such as sorbitol, xylitol etc.). Data related to sugar alcohols, a type of carbohydrate-based reduced-calorie sweetener, was not included in the review.
The main findings of the review, which the WHO used to support their recommendation, included:
- Short-term randomised controlled trials (RCTs) demonstrated that adults who consumed higher levels of non-sugar sweeteners had lower body weight and lower body mass index (BMI) than those who consumed lower amounts or no non-sugar sweeteners.
- Long-term observational studies showed that consumption of higher levels of non-sugar sweeteners was linked to increased BMI and risk of obesity.
- Long-term use of non-sugar sweeteners was also associated with a higher risk of type 2 diabetes, cardiovascular diseases and mortality. However, significant effects of the consumption of non-sugar sweeteners on intermediate markers of such diseases such as fasting glucose, fasting insulin or blood lipids were not observed in the short-term RCTs.
What to keep in mind when reading the study’s conclusions?
- The evidence assessed has been evaluated as low certainty by the WHO and the recommendation is considered ‘conditional.’
This is because the data on long-term health effects comes from observational research which cannot prove direct cause and effect. As such the observed association between non-sugar sweeteners and disease outcomes might be influenced by other factors, such as intentional weight loss before the start of the study, people having other risk factors for disease or complicated patterns of non-sugar sweeteners use, that could potentially influence the body weight and NCD outcomes. As a result, the recommendation has been classified as ‘conditional.’ This means that policy makers from individual countries will need to consider how and whether to translate the recommendation within their specific national contexts.
- Evidence shows that sweeteners may have a role in weight management in the short-term.
Short-term studies show a reduction in energy intake and body weight when sweeteners are used as a sugar replacement in the diet of adults, adolescents or children. Data on beneficial health effects of sweetener consumption are strongly dependent on context (e.g., your body weight, whether sweetener are used as replacement for sugar in solid or liquid foods, how long you replace sugar with sweeteners for and the type of sweeteners).
- The recommendation is not relevant for people who have diabetes.
The guideline is intended to provide guidance on the prevention of unhealthy weight gain and diet-related NCDs, and not their treatment. For this reason, the review did not include studies performed in groups of people with diabetes.
- The WHO recommendation is specific to weight loss and NCD risk, and is not related to safety.
The study specifically looked at the link between sweetener use in the context of reducing free sugars intake, promotion of healthy diets and prevention of unhealthy weight gain and diet-related NCDs. It is not a toxicological assessment and is not related to the safety of consuming sweeteners within recommended use levels. The European Food Safety Authority (EFSA) has carried out safety assessments on all individual sweeteners before approving them for use in the EU.2
What do the authorities say?
As sweeteners are food additives, there are no recommendations on their consumption in the same way as we have recommendations for other nutrients like carbohydrates, proteins or fats. Rather, EFSA has set acceptable daily intake values (ADI) for each specific sweetener. Following the publication of the WHO guideline, it will be up to individual countries to decide whether to take any specific policy or regulatory measures regarding sweeteners.
Co-funded by the European Union (under grant agreement No 101124527). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Health and Digital Executive Agency (HaDEA). Neither the European Union nor the agency can be held responsible for them.