The question as to what is more influential in affecting children's predilections for unhealthy food -- taste or packaging -- would be more useful to explore, but was not fully brought to light within the construct of the study, given that children were offered an choice between two identical assortments of sweet treats and vegetables at the same time. The focus on cartoons advertising children's food is a distraction, says McWilliams, from the more difficult-to-control pressures that do influence childhood obesity. Parents that can afford healthy foods and parents that have the time and the energy to ensure their children have safe places to exercise tend to have slimmer children. It is easier to ban cartoon advertising for cookies, politically, then to end subsidizes to industrialized farms that make cheap, sweet corn syrup used in processed snack foods and to make urban areas safe places to play. McWilliams uses his own family as an unscientific sampling of children who love junk food, but because of parental guidance, availability of outdoor pursuits, and a parentally-enforced balanced diet are not obese.

Arguing...

The results of such studies will have an undeniable influence on how such foods are regulated and more data is required. For example, it would have been interesting to see what would have transpired if children were forced to choose between carrot sticks with a picture of Dora the Explorer and a plate of homemade chocolate chip cookies with no label. Does sugar content or cartoons exercise a greater sway over children's preferences: if the answer is the latter, than tinkering with marketing campaigns will do little to win the battle against childhood obesity.
References

McWilliams, James. (2010, July 22). What we know, and don't know about children and junk food. The New York Times. Retrieved August 2, 2010 at http://freakonomics.blogs.nytimes.com/2010/07/22/what-we-know-and-dont-about-children-and-junk-food/?scp=2&sq=childhood obesity&st=cse