Mark Allen, a Brigham Young University neuroscientist, Professor Diane Spangler and graduate student Tyler Owens recruited a control group of women who scored in the healthy range on eating disorder diagnostic tests.
The researchers conducted brain scans using magnetic resonance imaging while the women were shown pictures of women they did not know who were overweight.
The pictures activated parts of the brain that processes identity and self-reflection. Men who were shown pictures of overweight men did not show signs of any self-reflection, the study said.
The women had no history of eating disorders.
"Many women learn that bodily appearance and thinness constitute what is important about them, and their brain responding reflects that," Spangler said in a statement.
"I think it is an unfortunate and false idea to learn about oneself and does put one at greater risk for eating and mood disorders."
The findings are scheduled to be published in the May issue of the journal Personality and Individual Differences.