Background
Weight stigma impairs health. Few studies have disentangled the associations of experienced versus internalized stigma with weight-related outcomes.

Purpose
To examine weight and health variables associated with weight stigma experiences and internalization in the largest-to-date sample of adults in weight management.

Methods
WW (formerly Weight Watchers) members (N = 18,769, 94.6% female, 91.1% white) completed an online survey from 2017 to 2018. Participants reported whether they had experienced weight stigma and, if so, the onset, past-year frequency and distress, and interpersonal sources of stigma. Participants completed the Modified Weight Bias Internalization Scale (WBIS-M) and self-reported: past-year weight and lifetime weight cycles; current self-monitoring behaviors; eating self-efficacy; physical activity; perceived stress; eating to cope; body image; and mental and physical health-related quality-of-life (HRQOL). Participants reported their demographic characteristics, including height and weight to compute body mass index.

Results
In logistic and linear regression analyses (controlling for participant characteristics), WBIS-M scores were negatively associated with weight loss, self-monitoring, eating self-efficacy, body image, and mental HRQOL and positively associated with weight gain, weight cycling, perceived stress, and eating to cope (p < .001). Experiencing weight stigma was associated with greater weight loss and less weight gain, although associations with other variables had small effect sizes (absolute β values < 0.10). WBIS-M scores remained significantly associated with all variables when including stigma onset, frequency/distress, and sources.

Conclusions
Internalized, but not experienced, weight stigma was consistently associated with adverse weight and health factors. Developing and testing interventions targeting internalized stigma in the context of weight management should be a research priority.