A low-sugar diet in utero and within the first two years of life can meaningfully reduce the risk of chronic diseases in adulthood, a new study finds.

Researchers determined that a low-sugar diet during the first 1,000 days after conception lowered the child’s risk of diabetes and hypertension in adulthood by 35 percent and 20 percent, respectively, and delayed disease onset by four and two years. Eating sugar in the first two years of one’s life directly shapes a person’s long-term health risks, the findings suggest.

“We all want to improve our health and give our children the best start in life, and reducing added sugar early is a powerful step in that direction,” Tadeja Gracner, corresponding author and senior economist at the University of Southern California (USC) Dornsife Center for Economic and Social Research, told The Epoch Times.

Dietary Experiences From Rationing: A Natural Scientific Experiment

Researchers from USC, McGill University, and the University of California–Berkeley studied how early-life sugar restrictions affect the risk of diabetes and hypertension later in life by comparing people conceived before and after the United Kingdom’s WWII food rationing program, which limited sugar intake from 1942 to 1953. The rationing program controlled the distribution of essential goods to ensure fair access for everyone during wartime shortages.

Those conceived shortly before rationing ended had mothers and early-life diets with low sugar intake, while those conceived after had more sugar in their early environment.

During the rationing period, people only consumed about 8 teaspoons (40 grams) of sugar daily, which falls within today’s dietary guidelines.

However, as soon as rationing ended, people’s sugar and sweets intake immediately shot up to almost 16 teaspoons (80 grams) per day. This increase is partly attributed to a rise in canned and dried fruit intake and a surge in sugar and sweets sales during the post-rationing period.

Early Life Nutrition Affects Adult Health

The study found that children exposed to rationing, both after conception and in early life, had a one-third reduced risk of developing Type 2 diabetes and hypertension when compared to those with little or no exposure to rationing.

Previous research has shown that the first 1,000 days from conception, including pregnancy (270 days) and the first two years of life, represent a critical window for fetal development.

“This period has been extensively studied and been shown as one of the most important developmental periods for several long-term outcomes,” said Gracner in an email.

The study references the “fetal origins hypothesis,” which suggests that a person’s risk of disease later in life is influenced by their experience inside the womb. When a fetus detects cues from the mother’s health—like poor nutrition—it makes adjustments to help it survive, such as changing how it uses energy and responds to hormones.

These adaptations can form “set points” that continue into adulthood. For example, if a fetus adapts to poor nutrition by slowing its metabolism, this slower metabolic rate can become a lasting set point, influencing how efficiently the body uses energy throughout life.

Additionally, infancy and toddlerhood are identified as “crucial periods for developing a taste for sweets (or even addiction) that can elevate sugar consumption throughout life,” the authors wrote.

“While humans generally like sweet taste, significant sugar exposure in early life can strengthen this preference,” Gracner said.

In their current work, her team finds supporting evidence of this pattern. “We found that adults who experienced sugar rationing consume less added sugar into their midlife compared to those who never experienced rationing,” she added.

While a mother’s low-sugar diet offered some protection, the reduced risk of development and delayed onset of chronic diseases were most pronounced when babies continued to experience a low-sugar environment beyond six months, typically when solid foods are introduced.

While maternal nutrition during pregnancy contributed one-third of the risk reduction, adding postnatal exposure to sugar rationing (up to one year) led to significantly greater reductions in disease risk. This effect was even more pronounced when rationing continued for over a year, especially for females. This may be because, as animal studies suggest, females are more likely to develop sugar addiction and poor glucose control in high-sugar environments, both of which increase the risk of Type 2 diabetes.

For those whose sugar exposure was restricted only in utero, Type 2 diabetes onset in older adulthood was delayed by about 1.5 years, and hypertension by half a year. However, people restricted both in utero and beyond one year postnatally had much longer delays: around four years for Type 2 diabetes and two years for hypertension.

This suggests that an infant’s early solid-food diet may have an even more significant impact on health outcomes than maternal nutrition during pregnancy. However, this hypothesis could not be thoroughly tested due to insufficient data regarding early-life and maternal diets in the UK Biobank, Gracner noted.

Broader Health Implications

Although the study primarily focused on the long-term effects of early-life low-sugar exposure on hypertension and Type 2 diabetes, its potential health impacts may extend beyond these conditions.

Gracner mentioned ongoing research investigating the effects of low-sugar exposure on chronic inflammation, obesity, cognitive function, and economic outcomes.

“We find suggestive evidence on decreased likelihood of chronic inflammation, obesity size, and economic outcomes, for instance,” she added.

Recommendations for Reducing Sugar Intake

The World Health Organization (WHO) dietary guidelines recommend that children under 2 should avoid free sugars, and adults and children over 2 should limit free sugar intake to less than 10 percent of their total energy intake, equivalent to about 12 teaspoons. Free sugars include all added sugars and naturally occurring sugars in juiced or pureed fruits and vegetables.

Reducing sugar intake to below 5 percent, or about 6 teaspoons a day, would provide even more health benefits, like reduced risk of overweight and obesity and tooth decay.

Added sugars (used in the study) are sugars added to foods during preparation or processing, like high-fructose corn syrup, glucose, molasses, etc. Foods with added sugars include:

• Sugary Drinks: sodas, energy drinks, sweetened teas, and sports drinks
• Desserts and Sweets: cookies, cakes, pastries, candies, and ice cream
• Breakfast Cereals: many cereals, even those marketed as healthy
• Flavored Yogurts: yogurts with fruit or flavoring
• Condiments and Sauces: ketchup, BBQ sauce, pasta sauces, and salad dressings
• Canned Fruits and Fruit Juices: canned fruits in syrup and some fruit juices
• Milk: chocolate- or vanilla-flavored milk and plant milks

Gracner emphasized the necessity of educating parents and caregivers about nutrition and holding companies accountable for providing healthier baby food options. Moreover, she noted that enforcing regulations regarding the marketing and pricing of sugary foods for children is essential.

“With better information, environment, and the right incentives, parents can more easily reduce sugar exposure—for their kids and themselves,” Gracner said. “All that said, we certainly don’t want to take away the joy of the upcoming holidays—a birthday cake, candy, or cookies in moderation are treats we all need to enjoy from time to time.”