STOCKHOLM, Sweden - As every western nation struggles with child obesity, the Swedes are puzzled by an unusual blip in the data: Why are little Swedish girls more likely to be fat than little boys?
A recent study by researchers at Sweden's Uppsala University shows that today's four-year-old girls are six times as likely to be obese as those 20 years ago - a bigger jump than among boys.
"This indicates that there is a relatively recent change in our lifestyles that is behind this," said Ulf Holmback, the lead researcher for the study published in the April issue of Acta Paediatrica. "But it's difficult to say what that is."
The weight increase itself was expected - Swedes, along with most other Europeans, have been getting heavier. From 1982 to 2002, the percentage of overweight four-year-olds has roughly doubled to 20 per cent for girls and 18 per cent for boys.
But obesity experts are scratching their heads over the gender difference that emerges in obesity rates. In 1982, just one per cent of all four-year-olds were deemed obese. By 2002, two per cent of the boys that age and six per cent of girls were obese. The discrepancy was similar for 10-year-olds.
Generally, a child 3锟� feet tall weighing 51 pounds would be considered obese; the same child weighing 44 pounds would be considered overweight.
"It's hard to come up with a smart explanation for this," said Carl-Erik Flodmark, head of the child obesity centre at Malmo University Hospital. "One biological explanation could be that boys are more active, and when the calorie load increases, maybe girls are more affected."
According to data compiled by the International Association for the Study of Obesity, IASO, the situation seems unique to Sweden.
IASO has compiled surveys from all European Union countries, and typically the differences in the obesity rates for boys and girls are very small. In countries that have large weight discrepancies among boys and girls - such as Greece and Estonia - it is the boys who have higher rates of being overweight.
And among adults across Europe, women generally are fitter than men.
Since 1980, when Swedes were among of the slimmest of western nationalities, obesity among adults has doubled to 10 per cent by 2005 in both sexes, according to Sweden's national statistics agency. However, roughly half the men are overweight compared with 36 per cent of the women.
That is still far lower than the United States, where recent government figures showed 71 per cent of men are overweight, and 66 per cent of women.
