A new study has found 75% of mothers and 77% of fathers think their overweight child is normal size.

Half the mothers, and 39% of fathers with obese kids also thought their children fell within normal boundaries.

The findings suggest that one of the biggest challenges facing health experts trying to tackle childhood obesity, may be ignorance.

Professor Sauer from the research group said, "It is vital that parents are aware of their children's weight if we are to prevent them becoming obese in later life."

He added, "The fact that the parents in our study perceived their children to be lighter than their BMI indicated is cause for concern."

800 parents were shown sketches of different sized children and asked to pick which one best represented their child.

Almost all parents chose a drawing slimmer than the one that their kids' BMI indicated. But whereas parents of normal weight children opted for one size thinner, parents of obese children were regularly picked three sizes too small.

"It is vital that parents are aware of their children's weight if we are to prevent them becoming obese in later life." said Professor Sauer.

"However, public perception of what is a normal weight has shifted upwards because more people are overweight or obese."

The study also looked at the relationship between the parents' weight and that of their children.

Mothers and fathers of overweight and obese children were heavier than the parents of normal weight children. However they were also more aware of their own size than they were of their children's, with the vast majority acknowledging they were too heavy.

The study was conducted by University Medical Centre Groningen in The Netherlands where an estimated 10% of the adult population is obese. In the USA the figure is 30% and in the UK it is 25%.

Parents of overweight and obese children did not think their children were less active than others and 94 per cent felt they could influence their child's food choices and eating habits.

Professor Sauer concluded that, "Our findings point to the need for health education programmes that encourage parents to recognise what is a normal healthy weight for their children and work with health professionals to tackle any weight problems."

Do you think this study highlights a real concern that misconceptions of what is a healthy size may be hampering the battle against obesity?

Do parents with overweight children need to wake up and accept that their kids are fat?