Food-brand knowledge predicts what kids will ask for later, said lead author Mimi Tatlow-Golden of the School of Psychology at University College Dublin.
The study included 172 children in Ireland, ages three to five years old, a quarter of whom were from Northern Ireland, where marketing regulations differ from the rest of the country.
Just over half of the kids attended school in a disadvantaged community, according to local government and education department data.
Parents filled out questionnaires about family demographics, eating habits and children's TV viewing alone and with others.
Researchers surveyed the kids at school one at a time, showing them nine food brand logos and product images, four belonging to healthy foods and five to less healthy foods, all of which are widely advertised in Ireland.
The researchers first asked kids if they knew the brand name of a food based on the logo, then if they knew what kind of food it was, then if they could match the brand logo to a picture of the correct food product.
Kids' scores on the brand questions rose for all types of foods between ages three and five, the authors report in the journal Appetite. On average, kids could name about a third of the brands, name the product type of half the brands and correctly match the images of almost two-thirds of the brands.
At all ages, kids were better at recognizing the less healthy foods. Their knowledge of unhealthy foods was most strongly predicted by how much unhealthy food their parents ate, and was not predicted by TV time or their mother's education level, the researchers found.
"We definitely couldn't conclude that marketing doesn't work, we just need to look beyond TV," Sandra Jones, director of the Center for Health Initiatives at the University of Wollongong in Australia, told Reuters Health.
Some of the healthy brands in the study, like Frube flavored yogurt in a tube and Cheestring string cheese, only refer to one specific food product, whereas the unhealthy brands, which included Cadbury's, McDonalds and Coca-Cola, produce a wide range of products, she noted. This could have skewed the results, said Jones, who was not involved in the research.
Image: Boy eating candy, via Shutterstock