Sugar Substitutes “Not Advised” for Weight Control According to the WHO

The World Health Organization (WHO) has published new guidance on the use of non-sugar sweeteners (NSS), in which it recommends they are not used to control body weight or reduce the risk of non-communicable diseases (NCD).

New guidance on non-sugar sweeteners

NSS – also referred to as sugar substitutes or artificial sweeteners – are commonly used as sugar replacements in food and drink products to maintain a sweet taste without a high calorie burden. While individual sweetener products are subject to toxicological assessments before they can be marketed as consumer products, evidence linking their effectiveness to specific health outcomes – such as weight loss – has been conflicting.

As the utility of NSS in reducing sugar consumption has increased over recent years, the WHO says it was “necessary” to review the available evidence and issue new guidance on NSS use, which was published this week. Here, the organization recommends against the use of NSS to control body weight and reduce the risk of NCDs. “The recommendation applies to all people except individuals with pre-existing diabetes and includes all synthetic and naturally occurring or modified non-nutritive sweeteners that are not classified as sugars found in manufactured foods and beverages, or sold on their own to be added to foods and beverages by consumers,” a press release issued by the WHO states.

How has this guidance been produced?

The guidance was produced based on a systematic review of randomized controlled trials (RCTs) and observational studies that explored the health effects of NSS use in adults, children and pregnant women. Studies were only considered suitable for the review if NSS were consumed in amounts within the acceptable daily intake (ADI), and studies involving diabetic individuals were not incorporated. “Because assessing the effects of NSS use in individuals with diabetes was beyond the scope of this guideline, studies specifically assessing the effects on individuals with pre-existing diabetes or including only such individuals were not included in the review,” the WHO guidance reads.

Overall, the WHO states that, based on available evidence, the use of NSS does not “confer any long-term benefit in reducing body fat in adults or children.” It is important to note that the guideline does not suggest NSS should be banned, as the review undertaken by the WHO was not focusing on chemical or safety issues.

"Replacing free sugars with NSS does not help with weight control in the long term. People need to consider other ways to reduce free sugars intake, such as consuming food with naturally occurring sugars, like fruit, or unsweetened food and beverages,” says Francesco Branca, WHO director for Nutrition and Food Safety. "NSS are not essential dietary factors and have no nutritional value. People should reduce the sweetness of the diet altogether, starting early in life, to improve their health."

The recommendation is conditional – why, and what does this mean?

The recommendation has been assessed as “conditional” by the WHO, due to potential limitations of the data analyzed, which include confounding baseline characteristics of study participants and complicated patterns of NSS use. “This signals that policy decisions based on this recommendation may require substantive discussion in specific country contexts, linked for example to the extent of consumption in different age groups,” the WHO says.

Members of the scientific community have also weighed in on the discussion with their opinions of the data and the subsequent guidelines. “Some specific limitations include the fact that most of the RCTs did not explicitly compare the replacement of sugar consumption with non-sugar sweeteners, so the conclusions about avoiding non-sugar sweeteners are based on indirect deduction,” says Professor Nita Forouhi, a physician scientist and programme leader of the nutritional epidemiology programme of the MRC Epidemiology Unit at the University of Cambridge.

Forouhi further emphasizes that individual NSS were not explicitly assessed and those included in the study were most likely to have been NSS that have been available for many years. Newer NSS, she says, may not have been as well represented in the analyses: “So, for the guidelines the NSS have been considered as a class of compounds collectively without distinguishing between individual types of non-sugar sweeteners.”

Thomas Sanders, professor emeritus of nutrition and dietetics at King’s College London notes that the report does not consider the effect of replacing sugar sweetened drinks with those sweetened with NSS. “There are high quality randomized controlled trials that show that when artificially sweetened drinks covertly replace sugar sweetened drinks in children, they help prevent unhealthy weight gain,” he says. Sanders believes that the guidelines may therefore cause confusion in the public health arena, because the “sugar levy in the UK has drink manufacturers replacing some of or all of the sugar with artificial sweeteners.”

Translating the guidelines will require concerted action

In its overview summary of the report, the WHO clearly states that the target audience for the guidelines are policy makers, non-governmental and other organizations, health professionals, researchers, educators and representatives of the food industry.

The guidelines feature recommendations on the use of NSS that can be harnessed by such individuals to address NSS use in their populations via public health interventions. “Translating the guideline into action will require concerted action from many players including policy makers, public health agencies, food manufacturers and ultimately also require a degree of behaviour change by individuals,” says Forouhi. “The goal is to reduce free sugars in the diet by replacing them with healthier, naturally occurring sweeteners such as from fruits and through unprocessed or minimally processed foods and drinks that improve overall diet quality.”