Dhaka, Sept. 27 -- A smartphone can put a world of appearance-focused content in a child's pocket, and new research suggests the age at which that happens may matter more than anyone realised.

Children who own a smartphone at age 12 are more likely to develop eating disorder symptoms than their peers without the devices, according to a new study.

The research, published Friday in the medical journal JAMA Network Open, draws on a wide-ranging survey of nearly 9,000 adolescents across the United States, CNN reports.

"A smartphone can put a world of appearance-focused content in a young person's pocket," said Dr Jason Nagata, the study's lead author, adding that this exposes children to images and messages that may foster unhealthy eating...