Is sugar in childhood really that harmful? Explore the latest research and tips to cut back on hidden sugars and protect long-term health!
Excess sugar has long been recognized as detrimental to childhood health, yet recent research continues to uncover the extent of its lasting effects. A study published in Science highlights that early exposure to high levels of added sugars is linked to increased risk of high blood pressure and type 2 diabetes in adulthood. These findings support a growing consensus that the optimal intake of added sugars remains significantly lower than what is commonly consumed during childhood.
Though excess sugar affects all age groups, early life appears to be a particularly sensitive period. “If exposure to sweet foods occurs early, a lifelong preference for them is likely to develop,” explains Tadeja Gracner, a scientist at the University of Southern California and coauthor of the study.
Sugar occurs naturally in foods such as fruit, but is frequently introduced during food processing and preparation. In the United States, average daily intake of added sugars among children reaches approximately 17 teaspoons—or nearly 300 calories.
This level far exceeds the dietary recommendation of limiting added sugars to less than 10 percent of total daily calories for those over two years of age. The World Health Organization suggests an even lower target of under five percent. For young children, the advised amount of added sugar is none at all.
Reducing this intake has been established as a priority in the U.S. government’s Healthy People 2030 objectives. Despite these efforts, sugar remains pervasive across the food landscape—not only in sweets, but also in soft drinks, cereals, savory processed foods, snacks, and even infant foods. Cultural norms further reinforce the association between childhood and sugary treats, with lollipops often offered at medical visits.
“It’s not that a treat should never be given. Reducing added sugar early is powerful for addressing long-term health.”
Tadeja Gracner
This perspective aligns with broader evidence showing that conditions in utero and during early development play a foundational role in shaping lifelong health outcomes.
Real-world Sugar experiment
A unique opportunity to observe sugar’s long-term effects arose from a real-world situation. During World War II, strict limits were placed on the purchase of sugar and sweets in the United Kingdom. These restrictions remained in place until 1953, well beyond the period directly influenced by wartime conditions.
This period of rationing allowed researchers, including Tadeja Gracner and colleagues, to examine the outcomes of early-life sugar exposure. By comparing individuals born just before the end of rationing with those born shortly after its removal—when sugar availability and consumption quickly doubled—clear differences could be studied.
Health data from approximately 60,000 individuals were analyzed through a large U.K. government database. Decades later, those who had experienced lower sugar intake during early development were found to have significantly better health outcomes. A 35 percent reduction in type 2 diabetes risk and a 20 percent lower risk of high blood pressure were observed among this group, compared to those born into an environment of unrestricted sugar access.
Sugar Health Impacts
The impact of added sugar begins early in life, with effects observed during childhood—not just later in adulthood.
Sugary foods tend to be high in calories, contributing to the current rate of childhood obesity in the United States. About one in five children are affected, including 13 percent of those between the ages of two and five. Obesity in early years has been linked to numerous health concerns.
A scientific report released by a federal nutrition advisory committee emphasized the importance of limiting sugar-sweetened beverages and processed snacks during childhood and adolescence. Reducing intake of salty snacks, red meat, and processed meats was also associated with a lower risk of obesity. As stated in the report, this approach is “associated with [a]… lower risk of obesity.”
High levels of added sugar are also linked to an increasing number of type 2 diabetes cases among children—a condition once considered limited to adults. Nearly 50,000 children are now affected. Research has shown that with each daily eight-ounce serving of sugary beverages, including 100 percent fruit juices, insulin resistance increases by 34 percent in boys.
Encouraging results were observed in a study involving 43 Black and Latino children with obesity. When added sugar was reduced to 10 percent of total dietary intake for just nine days, a drop in insulin levels was recorded. Significant reductions in liver fat were also noted, an important finding given the role liver fat plays in disrupting organ function and increasing the risk of serious conditions, including cancer.
Additional effects of high sugar intake during childhood include earlier onset of menstruation in girls and increased rates of dental cavities.
Although once widely believed to cause hyperactivity, sugar has not been shown to have this effect. That theory was disproven in the 1990s. However, some evidence points to other cognitive consequences. A study involving male adolescent rats indicated that early exposure to high levels of fructose may impair attention and increase impulsivity.
Added Sugars
Even small amounts of added sugar have been shown to produce noticeable effects on health. In a study involving young adults who consumed different levels of added sugar through sweetened beverages over a two-week period, increases in liver fat and blood cholesterol were recorded. While the most significant changes occurred in those receiving 25 percent of daily calories from added sugar, similar effects were also observed in those consuming just 10 percent.
“Differences were seen even in [that lower] group,” noted Kimber Stanhope, a nutritional biologist at the University of California, Davis, who led the study. Though the research focused on adults, comparable results are expected in most children—apart from those with extremely high levels of physical activity, where sugar may be used rapidly for energy.
Particular concern has been raised around high fructose corn syrup, found in many sweetened beverages and ultra-processed foods. This form of sugar combines fructose and glucose. According to Stanhope, the liver processes these sugars differently. While glucose delivery from the intestines is regulated by an enzyme, no such control exists for fructose. As a result, when large amounts are absorbed quickly, “a great deal of it ends up being stored as fat in the liver.”
These findings reinforce concerns about even moderate levels of added sugar and the impact on metabolic health.
Hidden Sugars
Becoming aware of hidden sugars in foods can be a powerful first step toward improving long-term health. Recognizing added sugars in everyday items often requires careful attention, as many forms appear under unfamiliar names such as maltose, dextrose, high fructose corn syrup, or even fruit juice concentrate. According to Joshua Tarkoff, a pediatric endocrinologist at Nicklaus Children’s Hospital in Miami, “which can sound good even though it isn’t.”
Simplifying food labels may support healthier choices. Research has shown that adding visual warnings to sugary beverages led to a 17 percent decrease in purchases. Until labeling becomes more transparent, focusing on categories of foods known to contain high sugar can help. Beyond cookies and candy, added sugars are found in a wide range of everyday foods.
Replacing sugary beverages with water can have a significant impact, especially since nearly two-thirds of children consume at least one sugar-sweetened drink each day. Juice at breakfast, chocolate milk at lunch, a sports drink in the afternoon, and soda at dinner can add hundreds of calories without providing lasting fullness. Labels claiming a drink is “100 percent natural” or “high in vitamin C” often lead to misunderstandings about its true impact.
Breakfast can be another hidden source. Many packaged cereals consumed by children function more like “a semi-liquid dessert,” according to Tarkoff. Plain oatmeal paired with fresh fruit offers a lower-sugar alternative to start the day.
Snacking habits are also important. Most prepackaged snacks contain large amounts of added sugar. The same applies to fast food. As Tarkoff notes, “Nature made sugar hard to get; man made it easy.” While processed foods offer convenience, more whole foods and meals prepared at home often result in lower overall sugar intake.
“People can get addicted to the comfort that their favorite high-sugar food brings and that pattern often begins in childhood.”
Kimber Stanhope
Although replacing sugar with artificial sweeteners may seem like a solution, concerns have been raised about potential health effects. Sucralose, one common substitute, has been associated with obesity, liver inflammation, and disruption of beneficial gut bacteria, according to a 2024 review.
Eliminating added sugar entirely may not be feasible. During the early years, caregivers influence eating habits, but greater independence comes quickly.
Offering sweet treats to soothe distress may also create lasting emotional ties to sugar.
“The goal is to try to teach kids boundaries—when to eat sugar and how much. The hope is then when they’re outside the house and able to eat what they want, the preferences you help set early in life will matter.”
Tadeja Gracner