The study showed that more than half of parents underestimated how fat their kid was.
It also found that a high number of doctors misjudge the weight of youngsters too.
Of mothers and fathers surveyed, a total of 54 per cent thought their child weighed less than they actually did.
The researchers – who presented their findings at the recent European Congress on Obesity in Glasgow – also discovered that parents also frequently used words such as “big boned”, “thick” or “solid” when discussing their child’s size.
Less educated parents, those who were overweight themselves or people with younger children were more likely to misjudge how fat their child was.
“Despite attempts to raise public awareness of the obesity problem, our findings indicate that underestimation of child higher weight status is very common,” said Abrar Alshahrani, the lead study author from the University of Nottingham.
The researchers looked at 24,774 children and their parents in 87 global studies to draw their conclusions.
“Nobody wants to think of themselves or their child as overweight or unhealthy,” said Professor Helen Stokes-Lampard, chairwoman of the Royal College of GPs.
“But the stark truth is that overweight and obese children face numerous, serious health-related problems – both physical and mental – in the years ahead, if their weight is not addressed.”
“This study shows how underestimation is prevalent across the board – including amongst healthcare professionals – and highlights the importance of taking accurate measurements, so that appropriate and consistent interventions can be implemented to support a child to lose weight and live a healthier lifestyle.
“It also emphasises how vital it is to be frank about weight from an early age as forging healthy behaviours in early life will have a very real impact on a patient’s long-term health and well-being into adulthood.”
Data from 2017 to 2018 show ed that 2.8 per cent of English children in school Reception year – who are aged between four and five – were overweight, while 9.5 per cent were obese.
In Year 6 – when kids are aged between 10 and 11 – there were 14.2 per cent who were overweight and 20.1 per cent obese.
“Millions of parents are in denial about their own and their children’s weight and they are doing their kids no favours at all since, as the researchers point out, they are denied the help to prevent them spiralling into becoming seriously overweight or obese,” said Tam Fry, chairman of the National Obesity Forum.