Will junk food lower your child's IQ?

Feeding toddlers a steady diet of processed foods could lead to more than just obesity — it could lower their IQs, according to a new study. Researchers at England's University of Bristol found that a child's eating habits at age 3 may influence his cognitive abilities at age 8. Toddler diets high in fat and sugar were associated with lower IQ scores, while healthier eating was tied to higher scores. The report, which appears in the Journal of Epidemiology and Community Health, is being billed as "the first study to suggest a direct link between the diet of young children and their brainpower" years later. Here, a brief guide to the findings:

How was the study conducted?

The researchers examined data on nearly 4,000 children born in the early 1990s, including detailed information from parents on what the kids ate and drank at specific ages. It also included the results of IQ tests performed when the children were 8.5 years old. The researchers sorted the kids into three categories based on whether they were given a "processed" diet full of fat and sugar; a "traditional" diet of "meat, potatoes, bread and vegetables"; or a "health-conscious" diet heavy on salad, fruit, rice, and fish. They also rated the kids' diets on a point scale, "which ranged from minus two for the most healthy to 10 for the most unhealthy."

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What exactly did the researchers find?

At age 8.5, the kids who'd been fed the worst diet as toddlers had slightly lower IQs than the kids with the healthiest eating habits. Every one-point increase in the 12-point unhealthy food scale was associated with a 1.67-point drop in IQ. That correlation held even after researchers adjusted the data for other factors like socioeconomic status and parental education. Improving a child's diet after age 3 did not seem to correlate to a jump in IQ.

Why are the first three years so important?

That's when the brain grows as its fastest rate and it is "possible that good nutrition during this period may encourage optimal brain growth," the study says.

How worried should you be?

"The kids most affected by this IQ loss were eating predominantly processed foods," says Sierra at Strollerderby. "That means... a whole diet of stuff that comes in tubes and boxes." Parents should give their kids fresh foods as much as possible, the researchers say, but a cookie here and there isn't terrible. "This doesn’t mean you should never give your child a fizzy drink, chips, or pizza, but these foods and drinks shouldn’t dominate the diet," says Dr. Pauline Emmett, one of the study's authors.

Sources: Daily Mail, Globe and Mail, Fox News, Time, Telegraph