Babies who are fed whenever they are hungry have higher IQs than those who are fed on a schedule, a new study has found.
The research published in the European Journal of Public Health suggests a significant difference in the mental abilities of "demand-fed" and "schedule-fed" babies.
Researchers studied data from a child development study of more than 10,000 children between the ages of five and 14.
On average, children who were demand-fed as babies had IQ scores four or five points higher than those who were schedule-fed.
"This difference between schedule and demand-fed children is found both in breastfed and in bottle-fed babies," explains Dr Maria Iacovou, who led the research from ISER.
"The difference in IQ levels of around four to five points is statistically highly significant. However, at this stage, we must be very cautious about claiming a causal link between feeding patterns and IQ.
"We cannot definitively say why these differences occur, and more research is needed to understand the processes involved."
The research is the first large-scale study to investigate the long-term outcomes of schedule-fed versus demand-fed babies.
It was carried out by researchers at the Institute for Social and Economic Research at the University of Essex and at the University of Oxford.