Your kids' cravings for yet another burger and fries meal could come with a side order of severe asthma, eczema or rhinoconjunctivitis, New Zealand researchers warned Tuesday.

A large international study led from the University of Auckland showed that an increased risk of the illnesses in adolescents and children is associated with eating fast food three or more times a week.

The research, which covered more than 319,000 teenagers in 51 countries and more than 181,000 children in 31 countries, also showed that the consumption of fruit three or more times a week was associated with a protective effect.

Principal authors Professor Innes Asher and Philippa Ellwood, of the Department of Paediatrics, said in a statement from the university that the findings could have huge implications for public health.

The teenagers and the children's parents were asked about the prevalence of symptoms of asthma, rhinoconjunctivitis, which produces a runny or blocked nose accompanied by itchy and watery eyes, and eczema, and about their weekly diet.

The focus was on the severity of symptoms over the preceding 12 months and on certain types of food that had already been linked to protective or damaging effects on health.

These included meat, fish, fruits and vegetables, pulses, cereals, bread and pasta, rice, butter, margarine, nuts, potatoes, milk, eggs, and fast food/burgers.

The analysis showed that fast food was the only food type to show the same associations across both age groups, prompting the authors to suggest that "such consistency adds some weight to the possible causality of the relationship."

It was consistently associated with current and severe symptoms of all three conditions among the teenagers -- across all participating countries, irrespective of gender or levels of affluence.

The pattern among children was not as clear-cut, but a fast food diet was still associated with symptoms across all countries.

However, the difference might have to do with the fact that children had fewer options about their food choices, suggested the authors.

Three or more weekly servings were linked to a 39-percent increase in risk of severe asthma among teenagers and a 27-percent increase in risk among children, as well as to the severity of rhinitis and eczema overall.

On the other hand, fruit seemed to be protective in both age groups for all three conditions among children and for current and severe wheeze and rhinitis among the teenagers.

Eating three or more weekly portions was linked to a reduction in symptom severity of between 11 percent and 14 percent among teens and children, respectively.

The authors suggested there were plausible explanations for the findings: fast food contains high levels of saturated and trans- fatty acids, which are known to affect immunity, while fruit is rich in antioxidants and other beneficial compounds.

They emphasized that their results, published online in the respiratory journal Thorax, did not prove cause and effect, but did warrant further investigation.

 Source: Xinhuanet