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Should you stop using sugar substitutes? Answers to common questions.

The World Health Organization wants people to cut back on all sweeteners, not just sugar

May 16, 2023 at 5:32 p.m. EDT
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8 min

On Monday, the World Health Organization issued a startling new report urging people to cut artificial sweeteners and other sugar substitutes from their diets. But that doesn’t mean you should switch back to using real sugar, the agency said.

WHO has already issued guidelines urging people to limit the amount of sugar they eat. Now the agency wants people to cut back on all sweeteners, period — whether they’re natural or artificial.

“Treat them as an element of the diet which we should discourage,” said Francesco Branca, the director of the department of nutrition for health and development at the WHO. “Sugar sweeteners do not belong to a healthy diet. That’s what we want to say.”

Reactions to the report have been mixed. Industry groups, including the Calorie Control Council and the International Sweeteners Association, said the safety of non-sugar sweeteners has been firmly established and that low- and no-calorie sweeteners have been proved to help with weight management and cutting back on calorie and sugar intake.

Others applauded the finding, saying people already eat too many ultra-processed foods, which have been linked to health problems, and the advice should encourage consumers to reduce their intake of both sugar and artificial sweeteners.

Here are answers to some common questions.

What sweeteners does the WHO advise against?

The WHO is advising people to stop using all artificial or non-sugar sweeteners. The guidance applies to individual sweetener packets that people may add to food and drinks as well as ultra-processed foods that contain the sweeteners. This includes:

  • Acesulfame K
  • Aspartame
  • Advantame
  • Cyclamates
  • Neotame
  • Saccharin
  • Sucralose
  • Stevia (and stevia derivatives)

Monk fruit extract isn’t on the list of sweeteners from WHO. It’s a relatively new addition to packaged foods. So, there’s less research available on its long-term effects. That said, “it is likely” that monk fruit extract may act the same as other sweeteners, Branca said.

Charles German, a preventive cardiologist at University of Chicago Medicine who studies how physical activity and a healthy diet can improve cardiovascular health, said the WHO’s new guideline is consistent with decades of research on artificial sweeteners.

“I certainly agree with the guideline, and I would imagine most physicians do,” German said. Most data and science has found that processed foods generally don’t benefit your health and are more likely to hurt it, he said.

What sweeteners are not included on the list?

Sugar, honey, agave and sugar derivatives — including corn syrup or sugar alcohols — are not considered “non-sugar substitutes” so they were not specifically named in the new WHO guidance. But that doesn’t mean people should switch to those products. In previous guidance, the agency already has recommended cutting back on all sugars. Sugar alcohols, also know as polyols, are commonly found in processed foods and come from plant products such as fruits and berries.

The goal is to cut back on both sugar and non-sugar sweeteners, Branca said.

“It forces people to think back to the very basics of ‘Okay, how can I have a healthier diet more broadly?’ Not just substituting one ingredient for another,” said Allison Sylvetsky, an associate professor of exercise and nutrition sciences at the Milken Institute School of Public Health at George Washington University.

What does the science show about artificial sweeteners and weight loss?

The WHO advised against using the sweeteners for weight loss. Branca said there are some rigorous clinical trials that show some short-term benefits to using artificial sweeteners for weight loss. But, when similar studies monitored participants for six to 18 months. there wasn’t the same effect on body weight.

“It may be in the short-term you do achieve that result, and some studies show that,” Branca said. “We don’t really have evidence to prove that weight is controlled using the sweetener.”

Barry M. Popkin, a professor in the department of nutrition at the University of North Carolina, said that artificial sweeteners can help someone with weight loss if they’re eating a healthy diet. But, the key is the sugar substitute has to fit alongside a diet of fruits, vegetables and less-processed foods.

People often concluded that foods or beverages with zero calories must “positively impact” weight loss. But, the reality is that isn’t always the case, said Katherine Zeratsky, a registered dietitian nutritionist at the Mayo Clinic in Rochester, Minn.

“Low-calorie or zero-calorie sweeteners might be an aid in weight management, but they are by no means the management or that silver bullet in weight management tools,” Zeratsky said. “It comes back to still being thoughtful about your food choices.”

What are the long-term health concerns about using non-sugar sweeteners?

Branca said the WHO’s review of the available research found groups who regularly consume non-sugar sweeteners had an increased risk of Type 2 diabetes and cardiovascular disease.

“We’re not saying that we have collected evidence for producing harm,” Branca said. “But, definitely, the evidence we’ve analyzed indicates it doesn’t produce a health benefit.”

Is it better to add sugar to my morning coffee instead?

“No, absolutely not,” said Thomas Sherman, professor of pharmacology and physiology at Georgetown University Medical Center. “I think people should use fewer sweeteners in general, but please do not react to this WHO announcement by switching to sugar.”

Instead of using two spoonfuls of sugar or two packets of artificial sweetener, cut back to one and then, maybe, none over time, experts say. The goal is to eventually get used to a diet without as much added sugar or artificial sweeteners. Zeratsky said she often recommends people cut back on sugars or sweeteners for a couple of weeks to “reset your taste buds” and try to appreciate the natural sweetness of a strawberry or carrot.

“Everybody would be healthier eating less sugar,” said Marion Nestle, an emeritus professor of nutrition, food studies and public health at NYU. “I mean, sugar doesn’t really do anything for your health. But, it adds to the pleasure of food.”

“There should be plenty of room in regular diets for sugar here and there,” Nestle said.

Younger, healthier people can still enjoy sugar in their morning coffee if they enjoy it, but moderation is key, said Qi Sun an associate professor in the departments of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health.

But, advice for people with certain metabolic conditions, Type 2 diabetes or elevated risks of heart disease are more steadfast. It’s best to avoid adding any type of sugar to your beverages if possible, experts say, as it can increase the likelihood that your condition worsens over time.

Does everyone agree on banning fake sweeteners from our diet?

Reactions have been mixed.

“I see the WHO recommendation as only introducing fear and confusion, and that is unfortunate,” Sherman said.

Sherman said he doesn’t recommend consuming nonnutritive sweeteners, but they can play a role for people trying to cut back on calories. “I don’t consume them myself. I don’t give them to my children. But I don’t fear them. I think there is a role in using diet versions of drinks to try to eliminate or lessen sugar consumption.”

Another concern is that the WHO’s guidance is based partially on a review of observational studies that found an association, not causation, between a person’s consumption of artificial sweeteners and their overall health. Theoretically, other parts of someone’s diet — not just their use of non-sugar sweeteners — may be a reason for long-term health issues.

“In many countries, the people who consume diet beverages are often very heavy,” Popkin said. The studies “don’t really look at the ones who have good diets versus bad diets, separately.”

Sun said there’s a lot of “heterogeneity” among the studies included in the WHO’s systematic review that guided its recommendation. Sun said that stronger evidence is still needed to confidently recommend banning non-sugar sweeteners from your diet. But, “there are much healthier beverages that you can drink,” he added, “like black coffee, water and tea.”

Artificial sweeteners are commonly found in ultra-processed foods and a growing body of research shows that cutting back on these foods can have “a huge impact on our health,” Popkin said. In a controlled clinical trial carried out by the National Institutes of Health, scientists fed a group of people a diet of ultra-processed foods for two weeks and then an equivalent diet from scratch. And, on the diet of ultra-processed foods, the participants quickly gained weight and body fat. As a public health message against all ultra-processed foods, Popkin agrees with the WHO’s guidance against consuming artificial sweeteners.

“Weaning us from sweetness is very important,” Popkin said. “We have too big a sweet tooth and, unless we cut it down, our children are going to have the same sweet tooth.”

Do you have a question about healthy eating? Email EatingLab@washpost.com and we may answer your question in a future column.

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