More than a quarter of children are on diets, including those of a healthy weight, new research suggests.

A study involving more than 34,000 youngsters in England found a rise in the proportion of children as young as eight trying to shed the pounds.

Data was analysed from 34,235 children aged eight to 17 that had been recorded as part of the Health Survey for England from 1997 to 2016.

It found a “significant increase over time” in the proportion of children reporting weight loss attempts, from 21.4% in 1997/98 to 26.4% in 2015/16.

The rise was from 5.3% (one in 20 children) to 13.6% (one in seven) among those who were a healthy weight.

Likewise, there was a jump from 9% to 39.3% for children trying to diet who were overweight, and from 32.9% to 62.6% for those who were obese.

According to the study, by 2015/2016 around one in five children aged eight to 12 and one in three children aged 13 to 17 were attempting to lose weight.

The likelihood of weight loss attempts was generally higher in girls than boys, but the increase over time was significant only for boys, said the researchers, including from the University of Oxford.

Older children were more likely to want to lose weight than those who were younger, as were those from Asian families or families with a low income.

Writing in the journal Archives of Disease in Childhood, the experts said there was a marked increase in weight loss attempts among children from 2011/12 onwards.

This coincided with parents being given feedback on their child’s weight as part of the National Child Measurement Programme (NCMP), which weighs and measures pupils when they are in Reception and Year 6.

The experts said: “A previous survey found that the provision of NCMP weight feedback increased recognition of childhood overweight and encouraged some parents to seek help, but it is also plausible that this prompted greater self-management.”

They said they were concerned that the increase in weight loss attempts “has not been matched by an increase in the provision of weight management services in England, creating a risk of unsupervised and potentially inappropriate weight control behaviours.

“Meanwhile, the rise in weight loss attempts among children with a healthy weight raises concerns and suggests greater attention is needed to target weight control messages appropriately.”

The latest NCMP data for England shows that 14.4% of children in Reception class were obese in 2020/21, up from 9.9% in 2019/20.

Among Year 6 pupils, who are aged 10 and 11, obesity prevalence rose from 21% in 2019/20 to 25.5% in 2020/21.

The experts behind the new study suggested that slimming attempts among all children are now outpacing rising weight gain in the same age group.

From 2009/10 to 2011/12, among older children (13 to 17), the frequency of weight loss attempts increased from just over 4% to 57.5% among those who were overweight, and from nearly 31.5% to almost 82% among those who were obese.

Tam Fry, chairman of the National Obesity Forum, said: “The news that more and more children appear to be taking their weight seriously is most welcome but this success must be greeted with a hint of caution.

“The survey stresses that its data are estimates rather than being precise but that can be easily overcome by the proposed extension of the NCMP.

“It is concerning that children with a healthy weight appear to be ‘dieting’ and they should be gently told to snap out of it.”