The more familiar a child is with unhealthy food logos the more likely they are to be overweight.

A research team that included a Michigan State University professor tested children between the ages of three and five on their recognition of fast food and junk food logos. The children who were able to correctly identify logos such as "golden arches, silly rabbits and a king's crown," tended to have higher Body Mass Indexes (BMIs).

"We found the relationship between brand knowledge and BMI to be quite robust," said Anna McAlister, an MSU assistant professor of advertising and public relations who was a member of the research team. "The kids who know most about these brands have higher BMIs."

The participants were given pictures of unhealthy food-related logos.

"The results varied, which is a good thing," McAlister said. "Some kids knew very little about the brands while others knew them exceptionally well."

The study was conducted twice; in one group the researchers found adequate exercise negated the link between too much familiarity with brand logos and higher BMIs.

"The inconsistency across studies tells us that physical activity should not be seen as a cure-all in fixing childhood obesity," McAlister said. "Of course we want kids to be active, but the results from these studies suggest that physical activity is not the only answer. The consistent relationship between brand knowledge and BMI suggests that limiting advertising exposure might be a step in the right direction too."

Since children get most of their knowledge of brand logos from watching TV it is unclear if brand familiarity or TV watching habits is linked to a higher BMI.

"From our results," McAlister said, "it would suggest that it's not the TV time itself, but rather what is learned about these brands. It's probably the developing food knowledge, not the sedentary lifestyle."

"What we're trying to show here is just how young kids are when they develop their theory of food," McAlister said. "As early as 3 years of age, kids are developing a sense of what food means to them."