Fruit sugar in an orange (© viperagp - stock.adobe.com)
VENICE, Italy — Sugar has had a bad reputation for decades. Studies have linked the sweetener to everything from tooth decay to Type 2 diabetes and weight gain. However, not all sugar is bad for you — it all depends on where it comes from. Researchers from the Netherlands have found that the source of the sugar children eat is more important when it comes to obesity than the amount kids consume.
The study's findings shift our understanding of childhood obesity. It reveals that the total amount of sugar consumed during early childhood is insignificant for weight gain at age 10 or 11. Rather, it's the source of sugar that contributes to poor health. Children who primarily consume sugar from sweetened snacks, such as cakes, confectionery, sweetened milk, and chocolate milk, are more likely to become obese.
Sugar from fruit, however, was associated with less weight gain. Additionally, those who got most of their sugar from unsweetened liquid dairy products such as milk and buttermilk were less likely to become overweight or obese.
“Fruit and unsweetened dairy products are considered healthy, they contain high amounts of intrinsic sugars—sugar that occurs naturally in the food, rather than being added. We wanted to know if the source of sugar, added versus intrinsic, as well as the amount, affects the likelihood of developing overweight or obesity,” says Junyang Zou, a professor at the Department of Epidemiology at the University of Groningen and University Medical Center Groningen, in a media release. “While this has been studied before, the results are inconsistent and there is a lack of high-quality research on the topic.”
The team collected health data from the GEKCO Drenthe study, a longitudinal study tracking the health and sugar intake of children born in the Northern Netherlands between April 2006 and April 2007. A food questionnaire was filled out by parents of 891 children when the children were three years-old. These responses were used to calculate daily total sugar intake and how much sugar was consumed daily from 13 food groups, including vegetables, whole fruit, cereals, meat, eggs, butter, milk, coffee and tea, sugar-sweetened beverages, ready-to-eat meals, and sugary snacks.
Nurses measured the height and weight of children from the age of three to 10 or 11. BMI Z-scores, which are often used to measure weight in childhood and adolescence, were calculated to measure obesity. They show how a young person’s BMI compares to the average BMI for their age and sex. Higher values mean a higher weight.
All 891 children had their BMI-Z scores calculated, but only 817 were included in the weight status analysis. Seventy-four children were excluded because they were already overweight or obese at age three.
On average, children ate 112 grams of sugar daily, which comprised 32 percent of their total daily energy intake of 1,388 calories. The main sources of sugar were fruit, dairy products, sugar-sweetened beverages, and sugary snacks. Researchers found 102 children who were normal weight at three years-old became overweight or obese by age 11.
However, the total amount of sugar eaten at three years did not have a link to weight gain later on during adolescence. However, eating a lot of sugar from snack products did have a connection to a higher BMI Z-score at age 11.
The opposite was true for fruit. Children whose sugar intake mostly came from fruit had a lower BMI Z-score. Children with high sugar intake from unsweetened dairy products like milk and buttermilk were 67-percent less likely to develop obesity at age 10 or 11.
The study did not look at why sugar from these different products affects weight differently. Possible explanations include a slower release of sugar from fruit than sugary snacks, which would keep children fuller for longer. Another theory is that different sugars affect the body in different ways. Cakes and confectionery items use sucrose, while fruit uses fructose sugar, and dairy uses lactose.
Regardless, Zou advises parents to give their children fruit and milk instead of sweetened milk and other products with added sugar.
The study authors presented their findings at the European Congress on Obesity in Venice, Italy.
