Pupils will have their weight, height and diet checked annually at school as part of a radical move to help combat soaring levels of childhood obesity.
Ministers have decided to revive the long-abandoned system of school medicals in England and Wales, even though they know that many parents may object.
But they have been swayed by warnings from medical experts that without regular measurement of what size children are, there will be no way of picking up the early signs that they are becoming overweight and offering them help to change their lifestyle.
Originally introduced at around the turn of the 20th century to help detect malnutrition, poor eyesight and stunted growth, medicals conducted by school nurses ceased to be common practice in the mid-Seventies. Only pupils at some independent school and a handful of state schools still receive them.
After several years of campaigners urging their reintroduction, John Reid, the Health Secretary, and Melanie Johnson, the Public Health Minister, have agreed to set up pilot schemes, probably in autumn 2006, and extend them to the rest of England and Wales later.
'We will look at height, weight, levels of physical activity that pupils do and their diet. The information will be used to keep track of children's health,' a Department of Health spokeswoman said.
Discussions are still ongoing about how the information will be used, but it is likely that parents of children who show signs of becoming overweight will be notified by letter and offered help.
A Department of Health document, explaining how the Public Health White Paper would be implemented, confirmed last week that it and the Department for Education and Skills are working together 'to develop appropriate systems for recording lifestyle measures, for example obesity through weight and height measurements, among school-age children'.
Ministers hope to avoid accusations of 'nannying' interference in family life by not making the checks compulsory. 'At the moment it's not compulsory, and there may well be legal problems if we tried to make it compulsory,' said a source involved in the inter-departmental discussions.
Tam Fry, honorary chairman of the Child Growth Foundation, a charity which promotes childhood health surveillance, welcomed the move. 'Given that one-third of the population is overweight or obese, this should help us pick up the early signs of a young person starting to become overweight, and offer them help to stop that any worse,' he said. 'The results will benefit children who have a problem, and reassure parents of those who don't.'
But he regretted that the checks would not be compulsory. 'In my view these checks should be universal because it's our duty to protect our children, and I think sometimes parents forget that, rather like immunisation, these measures are there to protect children. I fear some parents will not want their children to have them.
'These tests are non-invasive, and the information that parents get from them will either tell them that everything is fine or that they need to take action.'
The Labour MP David Hinchliffe, chairman of the Commons health select committee, which urged ministers last week to reintroduce weight checks, said the move was long overdue. But he urged the government to start them this autumn and make them mandatory.
'I understand that there are sensitivities in doing this around an overweight child being potentially labelled and stigmatised at school,' he said. 'But the scale of the challenge posed by rising levels of obesity mean we should be much bolder on this than the Department of Health is proposing.
'These checks should be very thorough, they should start when the new school years begins in September and they should not be voluntary. If we had still had them, we may have picked up on the growing evidence of an obesity crisis earlier.'
Dr Richard Taylor, a GP and the independent MP for Wyre Forest, in Worcestershire, who also serves on the select committee, said: 'When we were investigating obesity last year, we were amazed at evidence that many parents could not recognise when their children were overweight. That shows why we need these school medicals.'
Fry, of the Growth Foundation, said fewer school nurses - there were only 2,500 nationwide - meant some schools might have problems doing the checks.
