She began her magazine career in 1979, with a stint at Popular Science magazine. She was part of the start-up staffs for both Wigwag magazine, 1989–1991, and American Girl magazine American Girl (magazine), 1992-2000. Her 2006 New York Times article "One Spoonful at a Time" chronicled her daughter's descent into anorexia and recovery via family-based treatment, also known as the Maudsley approach. That article became the basis of her 2010 book, Brave Girl Eating. Her experiences inspired Brown to begin working as an advocate for better eating-disorders treatment. That same year she helped found Maudsley Parents, a website offering resources to families struggling with anorexia.
As a professor at Newhouse, Brown continues to write, research, and teach about eating disorders and body image. In 2009 she created Project BodyTalk, an audio and web project that collects commentaries about food, eating, weight, and body image. She writes for the New York Times science section and magazine, O: The Oprah Magazine, Health magazine, and many other publications. She lives in Syracuse, NY, with her family.