Scientists fear the high saturated fat levels may weaken children's immune system.
A research project involving more than 50 countries found that teenagers who ate food such as burgers three times a week or more were 39 per cent more likely to get severe asthma. Younger kids were 27 per cent more at risk, The Sun reported.
Both were also more prone to the eye condition rhinoconjunctivitis.
However, three weekly portions of fruit and vegetables may cut the risk by 14 per cent in the younger group and 11 per cent among the teens.
Researchers from New Zealand's Auckland University looked at the diets of 181,000 youngsters aged six to seven and 319,000 aged 13-14.
The study also asked if they had allergy symptoms. Researchers said their results do not prove cause and effect.
"Fast food may be contributing to increasing asthma, rhinoconjunctivitis and eczema. Regular consumption of fruit and vegetables is likely to protect against these diseases," researchers said.
The study was published in the British Medical Journal.
