A research study published in the journal Health Psychology explores the effects of belief in a just world on exercise and psychological well-being among individuals who have experienced weight bias. In Study 1, 804 participants in an online study reported belief in a just world; exercise intentions, motivation, self-efficacy, and behavior; experiences with weight bias; and height/weight and self-perceived weight status. In Study 2, 237 participants with overweight and obesity were randomly assigned to read 1 of 2 passages (online) describing weight bias and discrimination as rare versus pervasive, and rated their perceptions of pervasiveness. Participants then read 1 of 3 randomly assigned vignettes that confirmed, challenged, or did not attempt to influence belief in a just world, and completed measures of exercise intentions and motivation, body dissatisfaction, weight bias internalization, and experiences with weight bias. Results showed that Study 1 revealed that weaker belief in a just world was associated with lower ratings on all exercise variables among participants who reported experiencing weight bias. In Study 2, regression analyses revealed an interaction between ratings of perceived pervasiveness of weight discrimination and the Challenge condition for all outcome measures. The Challenge condition led to lower ratings of exercise intentions and motivation, and higher reports of body dissatisfaction and weight bias internalization, when weight bias was perceived to be more pervasive. The authors concluded that threats to belief in a just world may lead to negative outcomes for health behaviors and psychological well-being among individuals who have experienced weight bias and perceive it to be pervasive.