By Branwen Jeffreys
Health correspondent, BBC News
Obesity has been a factor in at least 20 child protection cases in the last year, the BBC has learned.
Child obesity rates are soaring
Some doctors now believe in extreme cases overfeeding a young child should be seen as a form of abuse or neglect.
The BBC contacted almost 50 consultant paediatricians around the UK to ask if they believe childhood obesity can ever be a child protection issue.
The British Medical Association is due to debate a motion on this issue at its annual conference at the end of June.
Earlier this year the case of one obese child hit the headlines when social workers became involved.
Dr Tabitha Randell, a consultant paediatrician from Nottingham, is one doctor who believes some parents are killing their children with kindness.
In her clinic it has become more common to see children entering puberty before the age of 10 because of their obesity.
In one extreme case Dr Randell saw a child aged two and a half who weighed more than four stone (25.4 kg).
"They said she was big-boned and they were too. I think the perception of parents is a very real problem.
"If you see every other child in the playground with their belly hanging over their trousers you think that's normal."
Some health professionals think it is unhelpful to see childhood obesity as potential neglect.
The Royal College of Paediatrics and Child Health said: "Obesity is a public health problem, not a child protection issue.
"There may be a few families that give cause for concern where there are other matters of neglect or emotional harm and this is where a paediatrician might have discussions with social services."
Some parents feel they face an uphill struggle to convince their children to eat healthily in a society where there are many high fat choices on offer.
At the children's centre in the deprived Meadows area of Nottingham parents are offered support to improve their children's diet.
A group of mothers has just signed up for a six-week course, learning how to prepare healthy food from scratch.
The mothers say it is too easy to blame parents.
Vikki Sansom, who has two young children, said: "I think there is a big difference between not feeding and overfeeding.
"It's really hard for parents and it's wrong to say that's neglect".
But at the end of June the BMA will be asked to consider the motion: "The government should consider childhood obesity in under-12s as neglect by the parents and encourage legal protection for the child and action against those parents."
Dr Matt Capehorn is the Rotherham GP who put forward the motion as a result of his own experience of running an obesity clinic.
He told the BBC: "My colleagues and I were concerned because we noticed a discrepancy in the way society, the medical profession and the courts treat an obese child compared with a malnourished child.
"There is outrage if a child is skin and bone but it only happens in extreme cases with obese children."
Doctors speaking anonymously to the BBC said overfeeding a child should be considered neglect in extreme cases:
"We're very lily-livered about this as a society. I have seen an obese child taken away from parents return to a normal body weight in a few months"
"I've seen a 10-year-old who could only walk a few yards with a walking stick. Her diet of chips and high fat food could firmly be laid at the parents' door. I believe they were killing her slowly"
"Seeing a 10-year-old with diabetes and high blood pressure. He is at risk of heart disease in his 20s - the family will not make changes"
"One 12-year-old boy came into hospital to be put on a diet. His family were caught smuggling in 1lb bars of chocolate for him"