Anti-fat bias is marked by a devaluation of overweight people compared with non-overweight persons. Even though belonging to the same group, research on social identity theory (SIT) indicates that overweight people also devaluate overweight others. Merging insights from research on anti-fat bias, SIT, and terror management theory, our study (n=101) provides new insights on motivational aspects of anti-fat bias by investigating the effects of existential threat on the evaluation of non-overweight and overweight people. Results revealed that participants in the existential threat condition displayed in-group bias: Participants perceiving themselves as non-overweight showed more pronounced anti-fat bias compared with participants in the non-death threat condition. In contrast, participants perceiving themselves as overweight demonstrated less anti-fat bias than controls.