Ultra-processed Foods in Young Children: What a Study Reveals About Their IQ Later

We know that our children's nutrition is crucial for their growth. But did you know that the contents of their plate at the age of 2 could have a direct impact on their cognitive abilities a few years later? A large Brazilian study has shed light on the link between ultra-processed products and a slight decrease in IQ (intelligence quotient) upon entering primary school.

Brain Development Begins in Early Childhood

The early years of life are a period of rapid growth for the brain. It is during this time that connections are formed and the foundations of memory and learning are solidified. To function at full capacity, this little biological engine needs quality nutrients. Brazilian researchers followed over 4,200 children from the Pelotas cohort since birth to understand how their eating habits influenced this development.

The study, published in early 2026, focused on two typical profiles: a "healthy" diet consisting of beans, fruits, vegetables, and natural juices, and an "unhealthy" diet rich in ultra-processed products. This includes instant noodles, industrial snacks, sugary biscuits, sodas, and cold cuts. By evaluating these children at the age of 2, and then administering IQ tests between the ages of 6 and 7, scientists observed a clear trend: a high consumption of processed products is associated with lower cognitive scores.

Ultra-processed Products Affect Concentration and Learning

The findings are striking, as the negative association between junk food and IQ remains visible even when researchers account for maternal education or the family's socio-economic level. Specifically, children with high consumption of these industrial products show a reduction in their IQ score compared to those who consume them sparingly.

This phenomenon can be explained by the nutritional poverty of these foods. Saturated with sugars, unhealthy fats, and additives, they often lack vitamins and minerals essential for the brain. In a 2-year-old child, even mild deficiencies can disrupt brain-building mechanisms. The study emphasizes that it is not an isolated food that poses a problem, but rather an overall dietary pattern where industrial products take up too much space.

Increased Vulnerability in the Most Fragile Children

One of the most important lessons from this research concerns children born with certain physical vulnerabilities. Researchers noted that the impact of poor nutrition was doubled in children who had early deficits, such as low birth weight, short stature, or a head circumference below average for their age.

For these children, a strong adherence to the "unhealthy" dietary profile results in a decrease of 4.78 IQ points, compared to 2.24 points in children born without specific deficits. This accumulation of factors shows that nutrition can act as a lever to protect or, conversely, further weaken the development of the most vulnerable children. This is valuable information for parents, as it proves that daily choices can help compensate for some initial growth delays.

Nutritional Balance is a Long-term Protection

While junk food pulls scores down, what about green vegetables and fruits? Surprisingly, the study did not find a spectacular link between a very healthy diet and a dramatic increase in IQ. In other words, eating broccoli will not turn your child into a genius overnight. However, this does not mean that a balanced diet is useless.

In reality, healthy eating acts primarily as a shield. By prioritizing whole foods like legumes or fresh fruits, one mechanically avoids excessive consumption of harmful processed products. The benefit is therefore indirect but real: a balanced diet ensures that the brain has everything it needs to reach its full potential without being hindered by inflammatory or overly sugary substances.

We are obviously not here to guilt parents who hand out industrial biscuits during long trips, but rather to emphasize the importance of simple products. The more the plate resembles a whole food, the better our little ones' brains will fare. By focusing on diversity and homemade options whenever possible, we give our children every chance to thrive in school and beyond.