The health of pupils eating school dinners is no worse - and in some respects may be better - than that of pupils eating meals provided from home, concludes a study published online by the BMJ today.

The nutritional content of school dinners has been causing great concern, yet little information is available comparing the health of school pupils who do and do not eat them.

Researchers examined the health of over 1,000 secondary school pupils across England and Wales. They assessed height, weight, and markers of fatness, such as waist and hip circumference, skinfold thickness, and percentage body fat. They also measured several chronic disease risk factors including blood pressure, blood sugar and cholesterol, and measured blood levels of folate (an important vitamin).

Pupils indicated whether they usually ate a school dinner, had a meal from home, or made other eating arrangements.

Compared with pupils eating meals from home, pupils who ate school dinners had lower levels of several risk markers for chronic disease including blood cholesterol, blood sugar and insulin. Leptin level (a marker of body fatness) was also lower. These differences held true, even after adjusting for factors such as social class, pubertal status and physical activity.

However, levels of folate were also lower among pupils eating school dinners. The authors suggest that the folate content of school dinners should be increased.

They also emphasize that, although the differences in chronic disease risk factors between pupils eating school dinners and those eating meals from home were modest, the average health status of pupils eating school dinners appears no worse - and in some respects may be better than - the health status of pupils eating meals provided from home.

"Current efforts to improve the quality of school dinners are to be applauded - the focus on fresh ingredients is welcome as this should increase vitamin intake (including folate)" says lead author, Professor Peter Whincup. "However, to improve the diets of British children and adolescents, we need to look beyond school dinners to address overall dietary patterns and their societal determinants."

School dinners and markers of cardiovascular health and type 2 diabetes in 13-16 year olds: cross sectional study BMJ Online First