There is a proliferation of websites, blogs, and social media accounts focused on providing weight loss, muscle gain, health and fitness information and products. Whilst there are positives to this focus on health and nutrition, the sharing of misinformation is problematic. Even when the information communicated has some supportive evidence and is not wholly inaccurate, the way in which messages are communicated can be harmful. This chapter provides a review of the literature relating to social and psychological harm of nutrition misinformation specifically by applying it to online contexts.