Individuals experiencing body dissatisfaction have poorer health outcomes in part due to engaging in less physical activity. Body appreciation is protective of health behaviors and proposed to be conceptually different from body dissatisfaction. Two studies evaluated whether body appreciation and dissatisfaction represented two distinct dimensions, and whether body appreciation and dissatisfaction would interact in their effect on activity-related motivation and behavior. Study 1 (n = 313) was prospective and utilized a self-report measure of physical activity whereas Study 2 (n = 123) was prospective and used an objective measure. All hypotheses and analyses were pre-registered. A multiverse approach was taken to demonstrate the robustness of results. In exploratory factor analyses, body appreciation and dissatisfaction did not represent two distinct dimensions of body image as both loaded onto the same factor. This result was largely supported by latent profile analyses, which revealed that participants scored high, moderate, or low on both body satisfaction and appreciation. Additionally, body appreciation did not buffer the negative impact of body dissatisfaction on activity-related motivation and behavior. This study provides the first statistical evaluation of the theoretical proposition that body appreciation and dissatisfaction may be distinct constructs with distinct relationships to outcomes.