The study watched at the relation between the eating habits of children at six months, 15 months and two years, and their IQ at eight years of age.
The study compared more than 7000 kids.
Children who were breastfed at six months and ate healthy had an IQ up to two points higher by age eight.
Healthy diet included legumes, fruit and vegetables at 15 and 24 months.
Children who ate biscuits, chocolate, lollies, soft drinks and chips in the first two years of life had IQs up to two points lower by age eight.
Smithers, L.G., Golley, R.K., Mittinty, M.N. et al. Eur J Epidemiol (2012) 27: 525. doi:10.1007/s10654-012-9715-5