The study, conducted by researchers at Uppsala University, involved two samples of children living in Uppsala County - a population in which there is a high proportion of post-graduate education amongst parents.
The aim was to assess whether there was a change in psediatric overweight and obesity prevalence over a twenty-year period.
Children in the first sample were aged four, 10 and 16 years in 1982, and those in the second were aged four, 10 or 16 in 2002.
The team measured their mean BMI (body mass index) in the lowest 10 per cent, mid 50 per cent, and highest 10 per cent, and calculated age-adjusted BMI cut-off values for each age and gender group.
They found that more four and 10-year-old girls and boys were overweight or obese in 2002 than in 1982, and the shift was larger in girls.
For the 16-year-old girls, however, only the middle 50 per cent group had a slight increase of their mean BMI.
In 2002, 22 per cent of four-year-old girls and 18 per cent of boys had a BMI over 25 (overweight), compared with ten per cent for both sexes in 1982.
Six per cent of the girls had a BMI over 30 (obese) in 2002 and four per cent of the boys, compared to one per cent for both sexes in 1982.
Amongst the ten-year-olds, 30 per cent of girls and 21 per cent of the boys had a BMI over 25 in 2002, compared to 14 per cent and eight per cent respectively in 1982.
While five per cent of ten year old girls had a BMI over 30 in 2002 compared to one per cent in 1982, the level for boys fell from two per cent in 1982 to one per cent twenty years later.
"Young children, especially girls, have become much more overweight/obese during the past 20 years, despite a high proportion of post-graduate education in the population," concluded the researchers.
"Children living in Sweden tend to be more active than children in other countries such as the USA.
But they spend more time in front of televisions and computers and tend to do less physical education at school than before" said co-lead researcher Dr Ulf Holmback, who is also a visiting research fellow at the University of Chicago, USA.
The food industry has shouldered some of the blame for the rising tide of obesity - but a concerted effort has been made in many markets to reduce use of detrimental ingredients such as sugar, salt and saturated fat.
Moreover, this month the first stage of restrictions of advertising unhealthy products aimed at children came into force in the UK.
However food industry groups have repeatedly stressed that food intake is only part of the problem - and therefore can only be part of the solution.
They have called for more action at a government level to encourage people to take more exercise and to help educate consumers on healthy lifestyles.
In particular, where children are concerned, schools and educational authorities have a role in teaching children healthy basics from an early age.
"As societies become more technological, various aspects of everyday life demand less and less physical activity and this is bound to contribute to childhood obesity," said the study researchers.
"And as overweight and obese children become overweight and obese adults they run a much higher risk of developing cardiovascular disease and type-2 diabetes."
"The lack of major change in 16-year-olds may suggest a rather recent change in the children's environment/lifestyle."
However Holmback and co-lead researcher Anders Forslund pointed out that weight data was missing from more of the 16 year olds in 2002, which could have been due to more overweight teenagers refusing to be weighed.
Study reference Publication: Acta Paediactrica Doi: 10.1111/j.1651-2227.2006.00189.x Title: Overweight more prevalent among children than among adolescents Authors: Ulf Holmbäck, Jennifer Fridman, Jan Gustafsson, Lemm Proos, Claes Sundelin, Anders Forslund