Fit For Sport, which conducted the tests, said parents and schools must do more to increase childrens activity levels.

London - As many as two out of three parents fear that talking to their children about their weight will lead to them getting an eating disorder.

Some believe that discussing the issue will lower their children’s self-esteem, while others avoid it even if their offspring are fat, says a survey.

Experts warn that parents are wrongly estimating their children’s weight by looking at them rather than making a simple calculation that will show whether they are overweight or obese.

The findings come from a survey conducted by the healthy lifestyles organisation Mend (Mind, Exercise, Nutrition... Do it!) and the Netmums parenting website.

The latest figures from the schools child measurement programme show a third of 11-year-olds are overweight or obese – so fat it threatens their health.

The new survey reveals that two out of five parents fear that talking about weight to their offspring will lead to an eating disorder. This rises to two thirds of parents who say their child is overweight or obese.

More than a third of parents (37 percent) feel that talking to their children about their weight might lower their self-esteem. Two in five parents have tried to do so, but almost half of those who had an overweight or obese child said it was an “unhelpful experience” for the family.

Two thirds of parents want more support in talking to their children about weight, increasing to 85 percent of those with fat children.

Almost three quarters of parents with overweight children said they found it difficult to help them stay healthy, mainly because they wanted to eat fatty and sugary foods.

Although they often talked to them about their eating habits – asking them to eat less junk food and more fruit and vegetables – more than half had never talked to them about their weight.

More than 1,000 parents with a child aged five to 16 responded to Netmums’ Let’s Talk About Weight survey, with one in six (15 percent) reporting that their child was overweight.

A third of all parents identified their children’s weight by looking at them or comparing them with others their age, rather than measuring it or getting it confirmed by a doctor.

Research shows that “sizing up” a child by sight alone often results in parents of fat youngsters wrongly believing they are a healthy weight.

Mend and Netmums are calling on more parents to find out if their child is a healthy weight by checking their Body Mass Index, a measurement that relates weight to height.

Children who have a high BMI and stay fat are more likely to have high blood pressure, cholesterol and blood insulin levels – all risk factors for heart disease – by the time they reach their mid-teens, say experts.

Paul Sacher of Mend said: “It can be very difficult for parents to tell if their child is a healthy weight or not simply by looking at them.

“The easiest way to check is to measure their weight and height, then use an online BMI calculator (’

Siobhan Freegard of Netmums said that although discussions about weight might initially be tough, “the family talking together and working together to find healthier ways of eating will lead to happier and healthier children”. - Daily Mail