Schools have been ordered to use more positive language when writing to parents to tell them their children are overweight.
According to new NHS guidelines issued ahead of the national school children 'weigh-in' in September, authorities are advised to use language that is "non-judgemental and positively phrased".
New letter templates are to be issued to local authorities ahead of the project, taking account of the fact that "parents receiving the letter may be sensitive to the information and feel that their parenting skills are being criticised."
Whereas before letters informed some parents that "Your child's result is in the very overweight range. Doctors call this clinically obese." Now schools are banned from informing parents that obesity can result in heart disease and some forms of cancer, and can only say that obesity can cause health problems in later life.
The National Child Measurement Programme, which is overseen by Public Health England, will feed in anonymous information on each child measured in order to enable the NHS to improve children's health services, and is "fundamental to efforts to tackle childhood obesity in England," according to the guidelines.
The letters will be signed by school nurses and contain contact information for advice and support services.
In June, doctors warned that there had been a four-fold increase over a decade in the number of children and teenagers admitted to hospital for obesity-related conditions.
While in 2000 872 overweight children received hospital treatment, in 2009 there were nearly 4,000 cases, according to the NHS.
Dr Ann Hoskins, Public Health England's director of children, young people and families, said: "We've listened carefully to feedback from parents and local authorities, and as a result the template letter has been simplified to make it easier to read and more personal."
Obesity has been linked to serious illnesses in childhood and an increased risk of developing conditions such as type 2 diabetes, asthma and breathing difficulties during sleep.
The UK has the highest rate of child obesity in Western Europe, which is estimated to cost the NHS around £4.2 billion a year.
Experts believe that increased consumption of junk food and sedentary lifestyles are behind the problem.