But this world is not kind to those who are overweight. A panda that aspires to be a martial arts master is told he'll never make it because of his "fat butt," "flabby arms" and "ridiculous belly." A chipmunk is called "fatty ratty." A donkey is called a "bloated roadside piñata" and told "you should think about going on a diet."

This is the world that's portrayed in the most popular children's movies (both live action and animated) released in the U.S. from 2006 to 2010, according to a mixed-methods analysis performed by an ensemble cast of researchers from the University of North Carolina at Chapel Hill. The examples cited above come from "Kung Fu Panda," "Alvin and the Chipmunks: The Squeakuel" and "Shrek the Third."

"These children's movies offer a discordant presentation about food, exercise and weight status, glamorizing unhealthy eating and sedentary behavior yet condemning obesity itself," said Eliana M. Perrin, MD, MPH, associate professor of pediatrics in the UNC School of Medicine and corresponding author of the study, published online Dec. 6, 2013 by the journal, Obesity.

In the study, Perrin and her co-authors analyzed the top-grossing G- and PG-rated movies from 2006-2010. Four movies per year were included, for a total of 20 movies. Segments from each movie were assessed for the prevalence of key nutrition and physical behaviors corresponding to the American Academy of Pediatrics' obesity prevention recommendations for families, prevalence of weight stigma, assessment of the segment as healthy, unhealthy or neutral, and free-text interpretations. With regard to eating behaviors, the researchers found that 26 percent of the movie segments with food depicted exaggerated portion size, 51 percent depicted unhealthy snacks and 19 percent depicted sugar-sweetened beverages.

With regard to depiction of behaviors, 40 percent of movies showed characters watching television, 35 percent showed characters using a computer and 20 percent showed characters playing video games.

Movie segments rated as "unhealthy" by the researchers outnumbered those rated as "healthy" by 2:1, and most of the movies (70 percent) included weight-related stigmatizing content.

"These popular children's movies had significant 'obesogenic' content, and most contained weight-based stigma," the study concludes. "They present a mixed message to children: promoting unhealthy behaviors while stigmatizing the behaviors' possible effects.