Kids love sweets. Of course, so do many adults. But even those grown-ups with a serious sweet tooth would likely struggle to polish off a big bag of candy, while the average kid would relish that chore. “Even during infancy, newborns have an innate preference for breast milk because of its sweetness,” says Juliana Cohen, an assistant professor of nutrition at Merrimack College in Northern Massachusetts and the Harvard School of Public Health.
Cohen says the prevailing theory is that a taste for sugary foods offered early humans an evolutionary advantage: In nature, sweet foods—stuff like fruits or honey—tend to be both safe and rich in calories, while bitter foods are more likely to be toxic. So humans may be born with an inherent desire for sugary foods that fades with age and eating experience.
This fade is a good thing. Studies have repeatedly linked high-sugar diets high to elevated rates of obesity, type 2 diabetes, and heart disease. “Added sugars,”—the type food manufacturers add to processed or packaged products, as opposed to those naturally present in whole foods—seem to be particularly unhealthy. The U.S. Centers for Disease Control and Prevention (CDC) recommends that adults limit their added-sugar intake to less than 10% of their daily calories, and a 2014 study in JAMA Internal Medicine found that people who exceeded this daily limit increased their risk of death due to heart disease by at least 30%.
Much of the research to date suggests that swallowing excessive amounts of sugar is just as dangerous for kids as it is for grown-ups. The CDC and the Dietary Guidelines for Americans both recommend that kids age 1 and older should, like adults, get less than 10% of their daily calories from sugar. The American Heart Association (AHA), meanwhile, recommends that children age two and younger should have no added sugar in their diet at all. But research presented last year by CDC scientists found that 60% of children under the age of 12 months consume at least some added sugar, and that the average daily added-sugar intake among kids between 1 and 2 years old ranges from 5.5 to 7 teaspoons, which works out to between 23 and 29 grams, approximately.
For older kids, meaning those ages 2 to 18, the AHA says daily added-sugar intake should not exceed 25 grams, which equates to roughly 6 teaspoons. Unfortunately, the average American youth blows past this safety threshold: data collected by the CDC show that, between 2009 and 2012, the average American child consumed 19 teaspoons of sugar every day, and that, depending on age, the average kid consumes somewhere between 11% and 17% of his or her daily calories in the form of added sugar.
How is sugar harmful to kids?
Cohen’s research has found that toddlers who drink beverages sweetened with added sugar, as well as children born to mothers who drank these beverages while pregnant, tend to score worse on childhood intelligence and aptitude tests. High fructose corn syrup, a sweetener that turns up in many artificially sweetened beverages—as well as in many packaged sweets—may be especially harmful. “It appears that high fructose corn syrup may be impacting hippocampal function during important periods of development,” says Cohen. The hippocampus plays an important role in learning and memory formation.
A 2018 Purdue University study found that the greatest source of sugar in the average kid’s diet is sugary beverages like fruit juice, soda, and sports drinks. A related 2015 study in the journal Nutrition found kids who consumed soda, fruit juice, and other sugary drinks tended to weigh more than kids who did not. Also, when some of the kids in the study swapped out their sugary juice or soda for either milk or water, their body weights tended to drop. More research has found that, as a child’s added-sugar intake rises, so does that child’s risk for hypertension, fatty liver disease, and type 2 diabetes, among other conditions.
Cohen and others say the message here isn’t that all sweets are bad, nor that kids should be wholly deprived of sugary treats. “Sugar in small doses is okay, but with the portion sizes most people are used to today, we’ve lost perspective on moderation,” she says.
“Sugar is added to foods so much more now than it was in previous generations,” says Jennifer Hyland, a pediatric dietitian at the Cleveland Clinic. “If you’re looking at food labels, you realize it’s hard to find foods marketed to kids that don’t have a lot of sugar in them.” Kids’ yogurt, breakfast cereals, applesauce, desserts, and juice all tend to be packed with sugar, she says.
Why is sugar such a popular food additive?
“The food industry knows that when they add sugar, you buy more,” says Dr. Robert Lustig, a sugar researcher and former professor of pediatrics and endocrinology at the University of California, San Francisco. Lustig says kids tend not to enjoy predominantly bitter or sour or salty foods. Adding sugar to these foods helps mask these tastes. “Sugar covers up the sour in lemonade, or the bitter in chocolate, or the salty in honey-roasted peanuts,” he says.
The obvious solution, recommended by most experts, is to avoid processed or packaged foods. For parents who don’t have the time or resources to prepare food from scratch, experts suggest shopping for peanut butters, breakfast cereals, and other packaged products that contain little or no added sugar. On the other hand, fruits, vegetables, unsweetened milk or yogurt, and other whole foods that naturally contain sugar are all healthy additions to a child’s diet.
But if you are going to do just one thing, you should encourage your children to drink water or milk rather than the sugary beverages that are the greatest source of added sugar in the average child’s diet.
“I don’t want parents to freak out and feel like they need to get rid of everything in their pantry,” Hyland says. “But we all need to be more aware of the added sugar in the foods kids are eating.”