A study in China found that blood levels of lead were 15 per cent lower in those who did not skip breakfast.

Scientists collected blood samples from 1,344 children aged between three and five and tested them for lead, iron, copper, zinc, calcium and magnesium.

Writing in the journal , researchers said lead poisoning was almost twice as common in boys than in girls, that children aged four and five faced double the risks of three-year-olds and that educating parents about nutrition was crucial.

Eating breakfast was also associated with greater zinc blood levels. Zinc is a vital micronutrient that helps strengthen the immune system.