WHO Advises Against Using Sugar Substitutes for Weight Loss

  • The World Health Organization (WHO) recently advised against the use of non-sugar sweeteners (NSS) in regard to weight management.
  • Non-sugar sweeteners are often used in weight loss efforts simply because of their ability to offer sweetness without the corresponding calories of sugar.
  • Experts emphasize the importance of understanding how sweeteners—both sugar and artificial—impact the body.

In landmark new guidance, the World Health Organization (WHO) has issued a statement advising against the use of non-sugar sweeteners (NSS) for controlling body weight.

In a May 2023 press release, the global health organization stated that this recommendation is based on the findings of a large systematic review conducted by WHO researchers, which suggested that the use of artificial sweeteners “does not confer any long-term benefit in reducing body fat in adults or children.”

Francesco Branca, WHO’s Director for Nutrition and Food Safety, cited a lack of evidence for the effectiveness of non-sugar sweeteners in keeping weight off long term, as well as potential adverse health outcomes from their use, including increased risk of type 2 diabetes, heart disease, and overall mortality.

The WHO statement makes no overarching claims about the safety of non-sugar sweeteners—and isn’t meant to scare people away from their use in general—but is rather a commentary on their impact on weight loss. That said, it’s a surprising shift from previous opinions regarding the role of NSS in weight management.

Here’s what experts have to say about the new guidance and what it means for the future of weight loss—with or without artificial sweeteners.

Woman pouring sugar into coffee

Woman pouring sugar into coffee

Getty Images / Alina Rosanova

The Complex Relationship Between Artificial Sweeteners and Weight Loss

As overweight and obesity have become greater concerns for the global population in the last several decades, researchers have sought solutions for helping people maintain a healthy weight.

Artificial sweeteners have appeared to offer promise.

“Non-caloric sweeteners, also known as non-nutritive sweeteners (NNSs), are often used as a strategy for weight loss based on the simple concept that they offer sweetness without the corresponding calorie load of regular sugars,” Kristin Draayer, MS, RDN, told Health.

“This would seem, on the surface, to create an obvious path toward weight reduction, and indeed, most short-term (less than one year) randomized controlled trials (RCTs) have shown that when NNSs are substituted for caloric sweeteners, weight loss can occur,” she added.

A 2020 meta-analysis in Obesity Reviews, for example, examined 20 studies that lasted at least four weeks, determining that non-sugar sweeteners led to significant weight reduction.

Another study from 2014 found that, over 12 weeks, people who drank non-sugar-sweetened beverages lost more weight than people who merely drank water.

Unfortunately, the research doesn’t paint such a rosy picture over the course of many years.

“The evidence supporting NNSs for weight loss becomes far less compelling when we extend the timeframe and look at long-term studies,” Draayer noted.

In fact, the WHO’s systematic review revealed that, though artificial sweeteners frequently helped people achieve short-term weight loss, longer-term cohort data with a follow-up of up to 10 years suggested an increase in body fat associated with their use.

The fact is, for most people, weight loss comes down to far more factors than merely replacing one ingredient (sugar) with another (non-sugar sweeteners).

“The physiology of weight loss is a multifaceted process involving hormonal responses, metabolic adaptations, and other physiological and psychological factors, all of which can impede weight loss maintenance,” Draayer explained.

“Adding NNSs to this mix doesn’t seem to change the fundamental nature of these challenges,” she continued. “The WHO’s new guidelines suggest that NNSs are not a silver bullet for weight loss as was previously hoped.”

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Are Non-Sugar Sweeteners Safe?

Besides highlighting the minimal effectiveness of NNSs for long-term weight loss, the WHO’s new guidance also raises questions about their safety.

The May 2023 press release mentions “potential undesirable effects from long-term use of NSS, such as an increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults.”

The systematic review on which the new guidance is based cites multiple studies that associated NNSs with heart attack, stroke, kidney disease, type 2 diabetes, and other adverse health outcomes.

It’s important to remember that many artificial sweeteners have a long history of safety when consumed moderately. In the U.S., the Food and Drug Administration (FDA) exerts tight regulations over the food supply, including artificial sweeteners. The FDA currently identifies eight non-nutritive sweeteners as “generally recognized as safe” (GRAS), including:

  • Saccharin
  • Aspartame
  • Acesulfame potassium (Ace-K)
  • Sucralose
  • Neotame
  • Advantame
  • Steviol glycosides
  • Luo han guo fruit extracts (monk fruit)

Some nutrition experts caution that any potential links between non-sugar sweeteners and health conditions should be taken with a grain of salt.

“It is important to be cautious about drawing conclusions from studies that only show an association and not a causation, as many additional factors can come into play when it comes to weight management,” Erin Palinski-Wade, RD, CDCES, author of 2 Day Diabetes Diet, told Health

“The same population who is already seeking out the use of NSS is the population that may be engaging in other dietary and lifestyle factors that may increase the risk of obesity, type 2 diabetes, and cardiovascular disease,” she explained. “This does not necessarily mean that NSS causes these conditions.”

Limiting Sugar Without Artificial Sweeteners

Whether or not you use artificial sweeteners, limiting sugar is still an important dietary strategy for achieving a healthy weight. There are plenty of ways to do so besides swapping a regular Coke for a diet Coke or adding a Splenda packet to your morning coffee.

“One of my favorite ways to sweeten foods is to use pureed fruit as a replacement for added sugars in baked goods,” Palinski-Wade advised. “You can use any pureed fruit such as banana, apples, or even prunes in a one-to-one swap for added sugar to provide all the same sweetness and moisture with no added sugar—while boosting fiber intake as well.”

Draayer suggested upping the flavor factor of dessert foods by experimenting with spices in place of some sugar. “Cinnamon, nutmeg, and vanilla can enhance the perception of sweetness while adding a ton of flavor,” she said. She also recommended substituting honey or maple syrup for white sugar, as their stronger flavors may allow you to use less of them.

Finally, remember that, in your efforts to lose weight, there’s no need to demonize any sweeteners, “real” or faux.

“Neither sugars nor non-nutritive sweeteners (NNSs) are inherently ‘bad.’ It all comes down to context,” Draayer emphasized.

“For example, switching from regular soda to a diet version could be helpful in avoiding the blood sugar spikes and crashes associated with sugary drinks,” she concluded. “On the other hand, choosing a sugar-sweetened cookie over a ‘diet’ cookie might be the better choice if it means more satisfaction and fewer feelings of deprivation, which could lead to overeating later on.”

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