More than a third of children are overweight or obese, according to a 20-year study of electronic health records.
However, a rapid rise in the problem may be starting to level off, at least in younger children, the findings indicate.
They looked at the anonymised electronic health care records of more than 370,500 children, aged two to 15, who had accumulated more than half-a-million weight (BMI/body mass index) assessments between them over a period of 20 years (1993 to 2013).
The analysis showed that between 1994 and 2003 the prevalence of being overweight and obesity in all children increased by just over 8pc each year.
But the rate slowed substantially between 2004 and 2013 to 0.4pc a year, suggesting it may have levelled off.
Trends were similar for both boys and girls, but differed by age group.
Among the boys, the prevalence of being overweight or obese among two to five-year-olds ranged from around one in five (19.5pc) in 1995 to one in four (26pc) in 2007.
These patterns were similar among girls. The prevalence ranged from 18.3pc in 1995 to 24.4pc in 2008 among the youngest, and from 22.5pc in 1996 to 32.2pc in 2005 among six to 10-year-olds.
The findings are published online in Archives of Disease in Childhood, one of more than 50 specialist journals published by BMJ.