Just when I was getting psyched to grill up a bunch of burgers and steaks this weekend, a medical study suggests that doing so could increase my kids' risk of developing asthma.

A major study of more than 50,000 children in 20 countries between 1995 and 2005 found that children who ate a lot of hamburgers were more likely to develop asthma than those who eat lot of fish, fruit and vegetables.

Researchers led by epidemiologists at Ulm University in Germany used parental questionnaires to collect information on allergic diseases and exposures to allergens from 50,004 randomly selected schoolchildren 8 to 12 years of age. The study published in the BMJ journal Thorax found that eating three or more burgers a week might boost the child's risk of asthma. Conversely, a Mediterranean diet was associated with a lower lifetime risk of asthma and wheeze.

"Overall more frequent consumption of fruit, vegetables and fish was associated with a lower lifetime prevalence of asthma, whereas higher burger consumption was associated with higher lifetime asthma prevalence," the researchers wrote.

The report follows an analysis published in the medical journal Circulation that found eating red meat was not associated with a higher risk of heart disease or diabetes in adults.