Rebekah Miller has four girls under 10. She’s not a “crunchy mom,” she says, eagle-eyeing everything to make sure it’s rigorously organic. But lately, she’s become worried about the blackberry-tea-flavored “drink enhancers” her daughters squirt into their huge water bottles each day.

Though the syrupy flavoring is packed with vitamins and advertises its “natural” ingredients, it’s also flavored with sucralose – one of many sugar substitutes increasingly showing up in food and drinks marketed for kids despite worries about their health impacts.

A woman picks up dinner at a grocery store in Glen Cove, N.Y. Carolyn Van Houten/The Washington Post

“You think you’re doing something great for your kids,” said the stay-at-home mom from St. Petersburg, Fla., explaining that the flavorings entice the girls into staying hydrated. “But now I’m thinking, should I be giving this to my 3-year-old, or my nearly 10-year-old who is going to go through puberty?”

It’s a dilemma faced by more and more parents as they heed the message to avoid added sugar but end up reaching instead for products crammed with artificial sweeteners. These snacks and drinks often have a healthful veneer, advertising that they are “low-sugar” or have “half the sugar” of previous formulas. The only indication that they contain sugar alcohols or chemical sweeteners may be the long list of ingredients on the back.

The goal of reducing sugar in kids’ diets is a noble one in a country where obesity has tripled since the early 1970s to about 1 in 5 children. But experts worry that parents may be swapping one evil for another, selecting ultra-processed products loaded with additives that haven’t been extensively researched in children. This week, a panel of the World Health Organization declared aspartame a possible carcinogen – 40 years after the sweetener was first approved by the U.S. Food and Drug Administration.

“I think we are embarking on a huge experiment with no control group, and including kids without parental consent,” said Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.

Today, there are dozens of sweeteners in the U.S. food supply, some of which were developed in the past few years. Consumers might struggle to find a snack or drink marketed to kids that is sweetened with just sugar anymore.

Quaker Chewy 25% Less Sugar chocolate chip granola bars, for instance, are sweetened with inulin, which is made from plants, and polydextrose, a complex carbohydrate made from glucose. Snack Pack Sugar-Free chocolate pudding is sweetened with sorbitol, maltitol, sucralose and acesulfame potassium, which are often combined to simulate the flavors and texture of sugar-sweetened treats. And Flintstones Immunity Support chewable vitamins, a product parents give to kids to keep them healthy? Four of the first five ingredients are sweeteners.

Even a new children’s drink co-founded by Michelle Obama – the former first lady who made childhood health a hallmark of her time in the White House – relies on sugar substitutes. PLEZi, which is advertised as low sugar and comes in flavors like Sour Apple and Blueberry Blast, is sweetened with stevia leaf and monk fruit.

Food manufacturers say they are responding to increased parent demand for sugar-free and low-sugar products and abiding by federal guidelines.

“We know some consumers are interested in sugar-free foods, so we look for solutions that will deliver on taste and comply with FDA regulations,” said Dan Hare, spokesman for Conagra Brands, parent company of Snack Pack.

“Providing a multivitamin with key essential nutrients to support kids in forms and flavors that kids will enjoy taking is important to our consumers,” said Nicole Hayes, director of U.S. external communications with Flintstones vitamins’ parent company, Bayer.

Some older sweeteners, such as sucralose, which is marketed under the brand name Splenda, have been studied repeatedly over many years and deemed safe by the FDA and regulators in other countries.

“Decades of research support the safety and efficacy of Splenda in healthy diets,” said Ted Gelov, chief executive of Splenda. He said Splenda, the top-selling sweetener brand, is considered safe by the FDA and that “over the years, numerous studies have proven that along with exercise and a healthy diet, reduced-calorie sweeteners are a critical tool that can help consumers manage body weight and reduce the risk of non-communicable diseases.”

WHAT IS HEALTHY?

But food safety over the long term is hard to study because researchers can’t control a subject’s diet over decades, and testing on kids gets even thornier. This has led to dramatic swings in nutrition guidance over the years.

Lydia Kives – an attorney, documentary producer and mother of two – lives in Beverly Hills, Calif., a community abundant with grocery stores that serve a health-conscious clientele. But she struggles with how to feed her kids healthy snacks, because food labeling can be confusing and because what’s considered “healthy” changes wildly from decade to decade.

“I think back to when my mother was navigating what to feed her family and margarine was the ‘healthy’ alternative to butter,” Kives said. The trans fats in many margarines have since been linked to higher rates of heart disease, “so I do proceed with a lot of caution with these alternative sweeteners.”

The surge of low-sugar and no-sugar products isn’t just a function of changing consumer preferences.

Last year, the FDA announced it would require foods labeled “healthy” to abide by strict limits on added sugars. Around the same time, the Biden administration announced more stringent nutrition standards for school meals, limiting added sugars across schools’ weekly menus to less than 10 percent of calories per meal.

As a result, food manufacturers are considering how to reformulate their products to get their added sugars under 10 percent of calories, with many of them turning to sugar substitutes.

“We must solve for sugar!” is the tagline for a new sugar alternative called RxSugar, made from allulose, a sweetener produced from corn and newly recognized as safe by the FDA. It is 90 percent lower in calories than table sugar because it largely isn’t digested by the body.

Some experts back the development and use of alternative sweeteners, citing the urgent health risk posed by high-calorie diets.

PLEZi Nutrition is unapologetic about its use of monk fruit and stevia, which are considered natural because they are derived from plants, and contain no calories. Kids are consuming far too much added sugar, Obama said during the product launch – on average, 53 pounds per year. Sugary drinks are the leading source of added sugar, and nearly two-thirds of youths consume sugary drinks on a given day.

“We know that hands-down the best thing for kids to drink is water and milk,” Sam Kass, co-chair of the PLEZi nutrition board who was also executive director for Obama’s Let’s Move! campaign, said in a statement. “We created PLEZi as a healthier alternative to sugary drinks that can compete on flavor while being less sweet – we use natural sweeteners to significantly reduce the overall sugar content because we know the outcomes of consuming too much added sugar are detrimental to our kids’ health.”

Kass said the goal with PLEZi products is to have less sugar, less sweetness and more nutrients, but that they have to taste good, “because otherwise, kids will just keep choosing soda and other sugary drinks.”

Willett, of Harvard, said that we can’t make generalizations about the health consequences of these sweeteners because they are all chemically different and almost certain to have different biological effects. The fact that some of these are “natural” products is no reassurance, he said, because “they may be consumed in unnatural amounts.”

“Table sugar is also natural but is clearly harmful when consumed in large amounts,” he said.

Stevia and monk fruit are derived from plants and are often viewed as safer than other sweeteners, but a number of studies have shown that stevia might lead to a microbial imbalance in the gut, and there has been almost no research published on the safety of monk fruit sweetener for children. Both are also sweeter than table sugar, which some experts say could prime children to crave ever-sweeter foods.

Food additives do not undergo as intensive of a review by the FDA as medicines. In 2016, the agency issued a rule that allowed companies to self-certify that a new chemical or food additive was safe. In the past 20 years, the FDA has allowed many sweeteners to be added to the food supply by accepting these studies and telling manufacturers they had “no further questions.”

WHAT THE SCIENCE SAYS

Emerging evidence has centered more on the impact of artificial sweeteners on the digestive system, which is increasingly believed to influence many aspects of our health. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill recently found that a chemical formed when digesting sucralose can cause DNA damage and make the lining of the intestines more permeable, though it’s unclear how much of the chemical ends up in the bloodstream. The authors of the study, which was conducted in a lab in test tubes and not on human subjects, said the results showed the need for further testing.

It isn’t even certain that these substances contribute to weight loss. A number of studies suggest that while in the short term, swapping out sugar for sweeteners may help people reduce calorie consumption, the use of sweeteners does not confer any long-term benefit in reducing body fat in adults or children.

Aspartame is in about 95 percent of carbonated soft drinks that have a sweetener and about 90 percent of ready-to-drink teas. A WHO panel said it may increase the risk of cancer, especially liver cancer, but the agency did not scale back its recommendations for how much is safe to consume each day. A number of studies have linked other sugar substitutes with cancer, diabetes in young adults and other illnesses, although they have often been inconclusive or contradictory.

But sweeteners have been strongly linked to the stimulation of taste receptors and increased food ingestion. And this may be a significant long-term problem, researchers say.

Julie Mennella, a biopsychologist specializing in the development of food and flavor preferences at the Monell Chemical Senses Center in Philadelphia, says that children by nature prefer higher levels of sweetness than adults. This is called the “bliss point.” Non-sugar sweeteners range from about 200 times as sweet as sugar (saccharin, aspartame, stevia and others) to 20,000 times as sweet (advantame).

“The bliss point for adults is like a Coke or Pepsi. Children are double that,” she said. “They live in a different sensory world.”

Luridly sweet foods for kids may entrench a lifelong predisposition to seek sweetness, but it may be worse than that. Some researchers think that ultra-processed food with heightened sweetness fits the description of “addictive.”

“Kids are being conditioned to respond with cravings, seeking a flood of dopamine in the brain,” said Joan Ifland, author of “Processed Food Addiction.” There is also a growing link between these foods and depression and psychological distress, she said.

“Manufacturers are putting these sweeteners in products that are also high in salt and fat, allowing them to trigger multiple pathways in the brain,” Ifland said. “These manufacturers are making their products addictive and remission-resistant.”

Even with all the right conditions – living in a community with easy access to healthful food, working from home, and having the time and energy to make most of her family’s meals – Kives knows she can’t avoid a flood of sweeteners.

“Obviously we know sugar is bad for kids. It affects their mood, their sleep – you name it,” she said. “But reading the labels is complicated. There are all these alternatives, and I have no idea what is actually safe, and in what amounts.”