American children are having trouble finding fashion to fit them as more and more of them become overweight, according to a report published by market research firm NPD Group.

The report, which is entitled 'Plus-Sized Children's Apparel: Insights and Opportunities', highlights the growing niche for oversize children's wear in the US which is yet to be filled.

The survey suggests that 31% of overweight 9-to twelve-year-old boys and 38% of girls in the same category are forced to wear men's and women's apparel as sizes designed for their age range prove too snug.

According to NPD's chief industry analyst, Marshal Cohen, many children struggle to find garments appropriate for their age group.

Cohen said that there have been double-digit sales increases in the youth plus-size clothing market over the past three years, but that there was resistance in department stores to embrace this clothing category for image and space reasons.

He added that plus-size apparel for this age range is appearing within the lower end of the market at present, as obesity tends to affect more people in this group.