The Body Positivity Movement (BP) arose from Fat Liberation and aims to promote body inclusivity and rejection of societal ideals around weight. There is evidence to suggest that BP may be beneficial in reducing risk factors for disordered eating (DE). While this is promising, there is no existing unified and user-generated definition of BP, and little is known about how BP is associated with anti-fat attitudes (AFA). Accordingly, Aim 1 assesses how young adult university students who identify as female define BP and how agreement with BP and fat liberation is associated with risk and protective factors for DE and AFA. Aims 2 and 3 assess how exposure to different types of BP content is associated with changes in risk and protective factors for DE and AFA. For Aim 1, 5000 female identifying undergraduate students between 18-25 years of age were sent recruitment emails via the Registrar’s Office at the University of Michigan to partake in a survey about social media and health. This cross-sectional survey assessed individual definitions and agreement with BP, fat liberation, as well as the following outcomes: eating disorder risk, body dissatisfaction, thin ideal internalization, body appreciation, body functionality appreciation, weight bias internalization, and AFA. For Aims 2 and 3, participants (N=224) were randomly assigned to view 10 condition-specific images and complete a battery of pre- and post-measures. Aim 2 examines if exposure to BP content with or without the presence of bodies compared to control images is associated with positive or negative risk factors for DE and AFA, such as state body satisfaction, state shape satisfaction, state appearance satisfaction, body functionality appreciation and AFA. Aim 3 examines if associations between exposure to BP content and risk and protective factors for DE, and AFA differ by body size of the image, more specifically between exposure to images of fat bodies, mid-size bodies(bodies that might be considered somewhat “overweight” (i.e., would not be categorized as the thin ideal, but are not likely to experience substantial AFA or discrimination)),” or a condition containing both fat and mid-size bodies. Independent repeated measure Analyses of Variance (ANOVAs) are used to examine differences in all outcomes from pre to post stimulus exposure. In Aim 1, it was found that young females (N=379) define BP as being primarily about “body love and confidence,” “appreciation of body diversity,” “not body shaming, “and “body acceptance,” “prioritization of health over beauty,” and the “rejection of societal ideals about weight and shape” (hereafter referred to as mainstream BP). Linear regression models revealed significant associations between agreement with mainstream BP and higher body functionality appreciation and lower AFA. Contrary to the hypothesis, there was a significant association between agreement with mainstream BP and thin ideal internalization. Agreement with fat liberation was associated with higher body functionality appreciation, lower eating disorder risk, and lower AFA. For Aim 2, there were significant increases in all measures of state body satisfaction for all conditions, but no significant effect of condition. In Aim 3, those who viewed images of BP content containing only fat bodies had greater increases in state appearance satisfaction. However, there were increases in all measures of state body satisfaction for all conditions. Findings from this study can be used to help public health professionals utilize mainstream BP and fat liberation to reduce DE risk and AFA.