Children fed healthier foods could be smarter than their junk food-consuming peers, Adelaide researchers suggest.
The study of more than 7000 children found those who were breastfed and went on to eat a balanced diet up to two years of age had a slightly higher IQ than those fed sugary treats.
Children's diet habits were examined at six months, 15 months and two years of age and their IQ was measured at the age of eight.
University of Adelaide Public Health researcher Dr Lisa Smithers said diet supplied nutrients needed for brain tissue development in the first two years of life.
"We found that children who were breastfed at six months and had a healthy diet regularly including foods such as legumes, cheese, fruit and vegetables at 15 and 24 months, had an IQ up to two points higher by age eight," Dr Smithers said.
"Children who had a diet regularly involving biscuits, chocolate, lollies, soft drinks and chips in the first two years of life had IQs up to two points lower by age eight."
The study compared a range of foods, including traditional and contemporary home-prepared food, ready-prepared baby foods, breastfeeding and 'discretionary' or junk foods.
The study was published in the European Journal of Epidemiology.