Game-playing kids, sat inside with their consoles while the real world goes on around them, risk getting the bone disease rickets, doctors say.
Professor Nicholas Clarke, from Southampton General Hospital, said he and his staff have examined more than 200 children for bone problems and found that more than 20 per cent of them had deficiencies that could prove dangerous.
"It is quite astonishing," a quite-astonished Clarke said. "This is a completely new occurrence that has evolved over the last 12 to 24 months.
"We are seeing cases across the board, from areas of deprivation up to the middle classes."
Clarke warned parents to take action before their kids end up knock-kneed.
Rickets is caused by low levels of vitamin D and renders children’s bones weak and easliy bowed.
The condition was rampant in the the UK from the 17th to 19th-centuries but was virtually wiped out in Britain in the 1930s, largely thanks to a daily dose of cod liver oil.
The doctors said that a diet of take-aways and ready-meals contributes to the problem
Just 20 minutes exposure to natural sunlight a day can to help the body keep the condition at bay, but it seems that 21st century British kids barely get that.
Justin Davies, a consultant paediatric endocrinologist, at the hopistal said: "This is almost certainly a combination of the modern lifestyle, which involves a lack of exposure to sunlight, but also covering up in sunshine, and we're seeing cases that are very reminiscent of 17th-century England."
Kids should ditch the computer and be made to walk to school the medics said.