A study has revealed that children who eat more fast food meals will grow up to have a lower IQ than those who regularly eat freshly-cooked meals.
Childhood nutrition has long lasting effects on IQ, even after previous intelligence and wealth and social status are taken into account, the study found.
The study examined whether the type of main meal that children ate each day had an impact on their cognitive ability and growth.
It looked at 4,000 Scottish children aged three to five years old and compared fast food with freshly-cooked food.
The study, undertaken by an academic at Goldsmiths, University of London, found that parents with a higher socio-economic status reported that they gave their children meals prepared with fresh ingredients more often, which positively affected their IQ.
Lower socio-economic status was linked to more children having fast food, which led to lower intelligence.
"It's common sense that the type of food we eat will affect brain development, but previous research has only looked at the effects of specific food groups on children's IQ rather than at generic types of meals," the Daily Mail quoted Dr Sophie von Stumm, from the department of psychology at Goldsmiths, as saying.
"This research will go some way to providing hard evidence to support the various high-profile campaigns aimed at reducing the amount of fast food consumed by children in the UK," she said.
Dr von Stumm said her findings highlighted that differences in children's meals were also a social problem.
"Mothers and fathers from less privileged backgrounds often have less time to prepare a freshly cooked meal from scratch for their children," she said.
"These children score lower on intelligence tests and often struggle in school.
"Schools in less privileged areas must do even more to balance children's diet, so that they can achieve their cognitive potential. It shows that the freshness and quality of food matters more than just being full, in particular when children are young and developing," she added.