The perception of obesity and the ideal body image has evolved over time, largely due to social norms that are not always guided by scientific knowledge. The use of social media for health promotion is an emerging area of investigation. Preliminary research suggests that they have the potential to both serve as a platform for combating the stigma of obesity and promoting positive body image. But there is also evidence that supports the contrary. In particular, the dissemination of digitally altered images that convey ideals of the slim female form can be detrimental to physical and psychological health. Further research is needed to determine how best to use social networks and media as a health promotion tool.