Overweight children are more responsive to food advertising and branding than kids in a normal weight range, according to a new study published in the journal Appetite.

The study looks at the quantity of food that children aged four to six choose to eat when they are free to munch on as much branded or non-branded food as they like.  Researchers were surprised by the results as they expected that all children, regardless of weight, would consume more when presented with branded foods.

The study found that overweight children ate about 40 calories more when presented with popular branded foods. Conversely, children who were not overweight actually consumed about 40 calories less when food was branded. There was also a difference between boys and girls: Girls ate about 40 calories less of the branded foods, while boys ate about 45 calories more.

The researchers also found that the children’s brand awareness was independent of whether parents reported buying a particular brand or not, suggesting that the home eating environment may not be the primary place that children become brand-aware.

The study, which appears in Volume 53 of the journal,  was supported by a grant from the National Institutes of Health and a Pilot and Feasibility Grant from the New York Obesity Research Center. The authors of the study are  Jamie Forman, Jason C.G. Halford, Heather Summe, Megan MacDougall, Kathleen L. Keller