Toddlers who eat more processed meats and sugary snacks at 2 show lower IQ scores by age 7

A new study says the first few years of life are very important for brain growth and intelligence, because the brain develops very fast during this time. Scientists wanted to see what kids eat at age 2 and how it affects their IQ at age 6–7. The research used data from 4,275 children from the 2015 Pelotas Birth Cohort in Brazil. Parents answered a food questionnaire to show what their children usually ate at age 2.

Researchers tested children’s intelligence later using a standard IQ test called the Wechsler Intelligence Scale for Children. Scientists found one “unhealthy diet pattern” that included packaged snacks, instant noodles, sweet biscuits, candies, soft drinks, sausages, and processed meats, as stated by Cambridge. Kids who ate more of these unhealthy foods at age 2 had lower IQ scores at age 6–7. The link between junk food and lower IQ was statistically strong, meaning it was unlikely to happen by chance.

Junk food and low IQ

Researchers also found that some children had early-life growth problems like low weight, short height, or smaller head size. These children were more affected by unhealthy diets, showing bigger drops in IQ scores.


Children with both poor early growth and unhealthy diet had about a 4.78-point drop in IQ. Children with unhealthy diets but without early growth problems still had a smaller drop of about 2.24 IQ points, as per Cambridge. Researchers adjusted results for other factors, and the link between junk food and lower IQ still remained.

What healthy food included

A healthy diet pattern included foods like beans, fruits, vegetables, baby foods, and natural juices. Surprisingly, scientists did not find a strong link between healthy diets and higher IQ scores in this study. Overall, researchers concluded that eating unhealthy foods early in life may harm children’s brain development and thinking ability. They also said children with early health or growth problems are at even higher risk from unhealthy diets.

FAQs

Q1. Does junk food affect a child’s IQ?

Yes, the study found kids who ate more processed snacks and sugary foods at age 2 had slightly lower IQ scores by age 7.

Q2. Are some children more at risk from unhealthy diets?

Yes, children with early growth problems like low weight or short height were more affected by unhealthy food.