Identifying oneself as being overweight may be associated with adverse health outcomes, yet prospective tests of this possibility are lacking. Over 7 years, we examined associations between perceptions of being overweight and subsequent health in a sample of 3,582 U.S. adults. Perceiving oneself as being overweight predicted longitudinal declines in subjective health (d = −0.22, p < .001), increases in depressive symptoms (d = 0.09, p < .05), and raised levels of physiological dysregulation (d = 0.24, p < .001), as gauged by clinical indicators of cardiovascular, inflammatory, and metabolic functioning. These associations remained after controlling for a range of potential confounders and were observed irrespective of whether perceptions of being overweight were accurate or inaccurate. This research highlights the possibility that identifying oneself as overweight may act independently of body mass index to contribute to unhealthy profiles of physiological functioning and impaired health over time. These findings underscore the importance of evaluating whether weight-feedback interventions may have unforeseen adverse consequences.