Underweight children are slipping through the net because of the nation's obsession with obesity, a conference has heard.
The European Congress on Obesity was told that one in 12 nine-year-olds was found to be worryingly thin in a recent study, adding up to two or three children in every school classroom.
The numbers of underweight children are also said to have trebled in the last 25 years, with scientists warning that being too thin could be worse for a child's health than being overweight.
Researchers told the conference that malnourishment is in danger of becoming a 'neglected disease in the developed world'.
A study at Essex University looked at 9,614 boys and girls aged between nine and 16 from in and around the Essex area. It found that 8.3 per cent – or one in 12 – were too thin for their height at the age of nine, and at 16-year-olds, the rate was 6 per cent, the same as the average figure across all age groups. In 1979, the average was was just 2 per cent.
Ayodele Ogunleye, one of the study's researchers, told the Liverpool-based conference that the results were 'quite alarming' and were likely to be even higher in poorer parts of the country.
He said that malnourishment is overlooked and not considered to be a problem in the UK. He added that rising food prices could be to blame for the increase, as families find it more difficult to pay for fruit and vegetables and high-protein foods. Other evidence suggested lack of physical exercise could lead to low weight in children as physical activity adds pounds by strengthening bones and muscles.
The study also found that girls were more likely to be underweight than boys - which Mr Ogunleye again put down to society's obsession with fat.
"We noticed that the prevalence of being underweight is higher in girls. Part of this is because society is obsessed about being obese," he said. "We feel the country is too rich for someone to be underweight, so it is just overlooked. I don't want being underweight to be a neglected disease in the developed world."
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