Parents are to be sent letters detailing their child’s height and weight to try to combat an obesity timebomb in Oxfordshire.

Oxfordshire Primary Care Trust (PCT) will record the statistics of children as young as four and then map them on a chart from 'underweight' to 'very overweight' for the special fat reports.

Specialist advice about diet and exercise will also be included in the letters, which will be sent to parents of four- and five-year-olds in their reception year and 10- and 11-year-old Year Six pupils.

Last night, parents welcomed the plan, but said they were worried the reports could lead to more bullying of overweight children.

Mother-of-four Claire Patrick, whose nine-year-old daughter has the tissue disorder Marfancorr Syndrome — causing her to be underweight — said: "It is a good idea. There are a lot of obese children nowadays.

"I think some parents might be quite embarrassed if their children are overweight. Some of the kids get picked on for being overweight and this might ‘up’ the bullying."

In February Oxfordshire health experts warned the county was facing an obesity timebomb when NHS figures revealed eight per cent of four-year-olds and 15 per cent of 10- to 11-year-olds were obese.

Another 12 per cent of reception year pupils and 13 per cent of Year Six pupils were classed as overweight in the study.

Reception and Year Six pupils in Oxfordshire are already weighed once a year for the Government’s National Child Measurement Scheme, but this year the PCT will send the results to parents as well as giving them to the Government.

The weigh-ins will take place in screened-off areas in schools from next month.

Parents who do not want their child weighed can opt out of the scheme and if a child is absent on the day of measurement, their statistics will not be sent home.

Government Health Minister Ivan Lewis who is behind the drive for the reports, said: "This isn't about pointing the finger and telling parents their children are overweight.

"Instead it is about equipping them with information to help their children lead healthier lives."

Marion Mills headteacher of Blewbury Church of England Primary School, near Didcot, said: "I think it is a good idea to do it — but there needs to be proper guidance.

"There should be a whole system where schools and parents and the authorities work together to tackle problems like this."

An Oxfordshire PCT spokesman said: "Parents have always been able to obtain their child's results by contacting the PCT, but now due to a high demand from parents we are exploring how to provide this information more succinctly.

"The Department of Health is advising that PCTs report back to all parents unless they have opted out of the programme."