This paper explores how young peoples’ personal and gender identities are shaped by mass media, in particular, through the production of body images. The study focuses upon the relationship between body images and eating disorders among young people (aged 11-17) in the United Kingdom (UK) and Hong Kong (HK). It employs the semiotic theory from the work of Saussure and Barthes to examine the symbolic representation of body identities. The work of Foucault will also be engaged to discuss the relationship between power and representation of gender identities. A survey was conducted and its results were used to illustrate the correlation between a desired body image and eating disorders by comparing the behaviours among secondary students in HK and the UK. The paper also highlights the significance of visual literacy in art education, which helps students critically evaluate the body images produced by the media.