Many parents are afflicted by 'weight-blindness', unable to recognise their child is overweight unless they are extremely obese, new research has found. The research discovered that just under a third (31 per cent) of the parents underestimated where their child's body mass index (BMI) was on obesity scale. The scale  classifies children as very overweight (or obese), overweight, a healthy weight, or underweight. Many parents are afflicted by 'weight blindness', and are unable to recognise their child is overweight unless they are extremely obese, according to new research (file picture) Just four parents described their child as being very overweight despite 369 children being officially identified as such (1 per cent) and fewer than 1 per cent overestimated their child's weight status. According to official guidelines, children are classified as overweight at the 85th centile and very overweight (or obese) at the 95th centile. The team estimated that for a child with a BMI at the 98th centile there was an 80 per cent chance that the parent would classify their child as a healthy weight. Tam Fry, spokesperson for the National Obesity Forum and chair of the Child Growth Forum said: ‘Because there are so many overweight and obese children around, the parents are in denial. 'They say “my Jonny is no fatter than the child down the road”. 'My advice would be that if any parent is concerned about their child’s weight, they should take the child to the doctor or chemist. ‘Think of an excuse to go down. Have the doctor or chemist take the BMI. 'When they have the result they can reassure the parent, or give them advice on whether the child’s weight is too high. ‘BMI is a very good measure, but it needs input from a health professional who can look at the child holistically and judge whether there is a problem or not. ‘Parents will not be able to measure their child accurately as they won't have the correct measurements for height and for weight bathroom scales are notoriously inaccurate. ‘They need to be properly measured by a professional who can make a proper judgement and give proper advice. ‘You cannot tell if a child is overweight or obese on one measure. 'You need to look at the child’s BMI and ideally plot this against their BMI three months ago.' However, they recognised that parents became more likely to classify their child as overweight when the child had a BMI above the 99.7th centile. The study found that parents were more likely to underestimate their child's weight if they were black or south Asian, from more deprived backgrounds, or if the child was male. Researchers suggested that if parents cannot identify when their child is overweight, this throws into question the effectiveness of public health campaigns aiming to address obesity in the home. Recent research found that a third of children in England are now classed as overweight or obese. Parents might underestimate their children's weight due to be fear of being judged, unwillingness to label a child as overweight, and shifting perceptions of normal weight because of increases in body weight in general. They said evidence suggests that parents who recognise their child's weight on the BMI chart are more likely to perceive potential health risks. The study was led by the London School of Hygiene & Tropical Medicine and UCL Institute of Child Health. It involved questioning the parents of 2,976 children in five primary care trusts: Redbridge, Islington, West Essex, Bath and North East Somerset, and Sandwell. The team said the research could help evaluate how effective public health interventions for obesity in children are likely to be in different groups of the population. Senior author Dr Sanjay Kinra, of the London School of Hygiene & Tropical Medicine, said: 'If parents are unable to accurately classify their own child's weight, they may not be willing or motivated to enact the changes to the child's environment that promote healthy weight maintenance.' Co-author Professor Russell Viner, of the UCL institute of Child Health, said: 'Measures that decrease the gap between parental perceptions of child weight status and obesity scales used by medical professionals may now be needed in order to help parents better understand the health risks associated with overweight and increase uptake of healthier lifestyles.' Graph, from the US' Centres for Disease Control and Prevention, shows how an a 10 year old boy would be considered healthy, underweight, healthy, overweight or obese depending on which percentile they are in on the BMI chart. A 10 year old with a BMI of 23 would be in the obese category (95th percentile or greater) The study was published in the British Journal of General Practice. Amanda McLean, director of the World Cancer Research Fund, said: ‘By encouraging children to eat healthily, maintain a healthy weight, and be regularly physically active, parents can help children develop healthy habits and protect against health problems later in life. ‘We know that obesity is linked to a range of health risks later in life – including increased cancer risk – so it’s vital that parents are aware of their child’s Body Mass Index (BMI), and can spot if their youngster is starting to become overweight. ‘But we also need to acknowledge that more can, and should, be done to encourage healthy eating and greater physical activity in our society. We need targeted policies that help people lead healthy lives – from clearer nutritional labelling to a focus on health education in schools. ‘By encouraging good habits we can help future generations lead happy, healthy, lives.’ World Cancer Research Fund’s Great Grub Club has plenty of advice and tools for parents to help their children get healthy in fun, easy ways. Parents who are able to recognise whether their child is overweight are more likely to perceive potential health risks and change their lifestyles, researchers said .
A third of parents underestimated their child's body mass index (BMI)
Just 1% of parents of obese children identified their child as overweight . Less than 1% of parents overestimated their child's weight, the study found . Experts: Recognising child's weight helps parents perceive health threats .