A disease caused by intolerance to gluten, a protein in wheat and other cereals, appears to start unnoticed in childhood before going on to affect one in 100 adults, research suggests today.

Fewer than one in 2,500 children is actually treated for coeliac disease - inflammation of the small intestine - but a study tracking thousands of children's medical histories has found 1% have antibody markers for the disease.

The children displaying antibodies, all aged seven, were on average 2.7cm (1 inch) shorter and 1kg (2.2lb) lighter than others, but otherwise showed no overt symptoms. Girls were twice as likely as boys to have antibodies.

The research, published in the British Medical Journal, comes from a study of 14,000 mothers and their children which began in 1991 and is based at Bristol University.

Gluten can damage the intestinal lining and reduce the gut's ability to absorb nutrients, causing diarrhoea or less obvious symptoms such as weight loss, tiredness or anaemia. The intestine generally returns to normal on a gluten-free diet.

Polly Bingley, from Bristol University, said: "We have found that the frequency of coeliac disease at age seven is the same as that we find in adults in this country, suggesting that the condition starts in childhood, even in individuals in whom it is diagnosed late in life."