The weight of stigma: cortisol reactivity to manipulated weight stigma

Rates of weight-based stigmatization have steadily increased over the past decade. The psychological and physiological consequences of weight stigma remain understudied.

This study examined the effects of experimentally manipulated weight stigma on the stress-responsive hypothalamic-pituitary-adrenal axis (HPA) in 110 female undergraduate participants (BMI: M=19.30, SD=1.55). Objective BMI and self-perceived body weight were examined as moderators of the relationship between stigma and HPA reactivity.

Results indicated participants' perceptions of their own body weight (but not objective BMI) moderated the effect of weight stigma on cortisol reactivity: F(1,102)=13.48, P<0.001, η(2) p =0.12 (interaction 95% CI range [-2.06 to -1.44, -1.31 to -0.99]). Specifically, participants who perceived themselves as heavy exhibited sustained cortisol elevation post-manipulation compared with individuals who did not experience the weight-related stigma. Cortisol change did not vary by condition for participants who perceived themselves as average weight.

In the first study to examine physiological consequences of active interpersonal exposure to weight stigma, experiencing weight stigma was stressful for participants who perceived themselves as heavy, regardless of their BMI. These results are important because stress and cortisol are linked to deleterious health outcomes, stimulate eating, and contribute to abdominal adiposity.