Many parents and children do not recognise that they are obese, and being overweight is increasingly seen as “the norm”, research showed today.

A study of 300 families found that mothers and fathers were not seeing that their children had a weight problem.

One third of obese girls and half of obese boys were described as “about right” by their parents.

The researchers, from the Peninsula Medical School, Plymouth, and Plymouth Hospitals NHS Trust, found that 40% of parents had no concerns about their obese child’s weight.

Alarming rise in children’s weight

Figures have shown an alarming rise in weight problems among children in recent years, prompting urgent calls from doctors and health campaigners to tackle the problem.

Among those aged two to four, obesity almost doubled between 1989 and 1998, from 5% to 9%, and among those aged six to 15, rates trebled from 5% in 1990 to 16% in 2001

Overall about one in five adults is now classed as being obese.

The latest research, being presented at the Diabetes UK medical conference in Birmingham, found that parents equally could not see their own weight problems.

The Earlybird Diabetes Study found that one third of women and half of men who were either overweight or obese rated themselves as “about right”.

Half of overweight or obese children also underestimated their own body mass index (BMI) - the scale used to measure whether you are the right weight for your height.

Illness risk

Being overweight can lead to illnesses such as diabetes, heart disease and cancer, as well as difficulties in moving about.

Benet Middleton, chief executive of Diabetes UK, said the rapid increase in cases of diabetes in the UK was partly due to weight problems.

“People underestimating their BMI category and beginning to see being overweight as the norm is a very worrying trend.

“Being overweight can lead to numerous health problems, including Type 2 diabetes, and it is essential that people realise if they have a weight problem.

“Obesity is a real problem and it needs to be tackled now.”

Parents were urged to keep an eye on their children’s eating habits and make sure they get enough exercise to prevent them piling on the pounds.

Obesity is measured by calculating your BMI - your weight in kilograms divided by the square of your height in metres.

In Britain, people with a BMI between 25 and 30 are categorised as overweight, and those with an index above 30 are classed as obese.