Psychobiological Processes in Social Evaluation

Higher-weight individuals face pervasive weight-related stigma and discrimination in their daily lives. There is conceptual and empirical evidence to suggest that weight stigma contributes to worse physical and psychological health outcomes, mediated by the deleterious psychobiological responses to psychosocial stress. Activating self-soothing emotional states (such as self-compassion) may protect against this psychobiological cascade, conferring resilience to negative social evaluation (such as weight stigma). This proof-of-concept study aims to establish the feasibility of an experimental protocol testing whether an acute self-compassion intervention can attenuate the psychobiological stress response to induced weight-based social-evaluative threat. Participants will be randomized into either self-compassion intervention or rest control groups. A standard body composition assessment will be used to induce weight stigma among young women who self-identify as "higher-weight." Stress-sensitive biomarkers (i.e., salivary cortisol and heart-rate variability) along with psychological indices of self-conscious emotions will be used to quantify the psychobiological stress response. This novel pilot study will contribute to efforts to understand the psychobiological processes by which self-compassion facilitates adaptive responding to acute stress, and will help inform future tests of interventions focused on mitigating the harmful health effects of social stigma.

This is a randomized proof-of-concept experiment with two conditions: self-compassion intervention and no-intervention (i.e., quiet rest) control.

The primary objective of this pilot study is to examine the feasibility and establish parameter estimates for a laboratory protocol to quantify the psychobiological responses to a lab-based weight stigma induction. Feasibility will include process assessments (i.e., examine acceptability of both the self-compassion intervention and weight stigma induction to participants, establish feasibility of recruitment goals and examine participant demand), resource assessment (i.e., test the practicality of the proposed experimental protocol), management assessment (i.e., test research group's ability to implement experimental protocol including self-compassion intervention, weight-based social-evaluative induction and biological biomarker collection), and scientific assessment (i.e., establish parameter estimates for psychological and biological responses to self-compassion intervention and social-evaluative threat induction). Due to the unpredictable nature of the COVID context for biological sample collection, no a prior criteria for feasibility are established.

The secondary objective is to perform limited-efficacy testing of the self-compassion intervention in reducing the psychobiological stress response relative to control condition. Efficacy will be assessed by comparing pre/post manipulation biological (i.e., cortisol, heart rate variability) and psychological (i.e., state shame, guilt, distress, internalized weight bias) indices between conditions (i.e., self-compassion intervention, rest control).

N=60 young adult cis-gender women who perceive themselves to be "heavier-weight" will be recruited to participate. After a brief telephone pre-screening interview to determine eligibility, participants will book two lab visits to complete a baseline assessment and experimental manipulation.

The first in-lab session will comprise of the informed consent process and computerized surveys to collect demographic and psychological baseline measures. This session will also serve as acclimatization to the lab environment, to minimize anticipatory anxiety and/or novel environment effects that may confound psychobiological stress measures during the experimental manipulation. After providing written informed consent, participants will complete a computerized survey consisting of demographic and baseline psychological measures.

All experimental sessions will take place between 1 pm and 5 pm to control for diurnal variation in cortisol and will be conducted in a light- and temperature-controlled laboratory. Participants will fill out a computerized survey to assess baseline psychological indices, and will provide a 5-minute baseline heart-rate variability measurement and saliva sample (#1).

Participants will be randomized into one of two experimental conditions: acute self-compassion intervention or rest control. Over the next 30 minutes, participants who were randomized into the self-compassion condition will be guided through a multi-modal behavioural self-compassion intervention. Participants in the no-intervention (resting) control group will be asked to sit quietly for 30 minutes. Immediately after the self-compassion induction (or control), participants will complete a measure of state self-compassion as a manipulation check and will repeat state psychological measures taken at baseline.

An anthropometric assessment including a standard three-site (triceps, iliac crest, thigh) skinfold body composition assessment, height and weight measurements will be performed by two thin researchers to induce weight stigma. Participants will undergo the assessment while wearing a physically revealing outfit (i.e., sports bra and spandex shorts) which they will be asked to change into at the beginning of the weight-stigma induction. This paradigm has been shown to successfully induce social evaluative threat in young women, eliciting cortisol and body shame responses.

Immediately after the weight stigma induction, participants will be asked to complete a brief survey assessing psychological outcome measures and to provide a saliva sample (#2). Then, participants will be asked to wait quietly for a 35-minute minute recovery phase, during which saliva samples will again be collected at 10 (#3), 20 (#4) and 35-minutes (#5) post-stressor.

After the recovery session is over, participants will be asked to respond to open-ended funnel debriefing questions to assess the believability of the cover story and the success of deception. Participants will also be asked questions related to the acceptability of the experimental protocol and social-evaluative induction. Finally, participants will be fully debriefed.

Eligibility Criteria:
Inclusion Criteria:

* Can read and communicate in English to provide informed consent
* Cis-gender woman (self-reports their gender as woman and assigned sex at birth as female)
* Age 18-34 inclusive
* Self-identify as "heavy weight"
* Currently taking oral contraceptives

Exclusion Criteria:

* Current smoking; current other nicotine/tobacco use; or current recreational drug use
* Current and active use of any oral prescription medication to treat a chronic health condition - excepting contraceptives
* Chronic health conditions as diagnosed by a licensed medical professional such as psychiatric (including substance use disorder, eating disorder), endocrine, cardiovascular, respiratory, autoimmune or other chronic conditions - excepting obesity, which will still be included due to inconsistent findings regarding whether obesity impacts neuroendocrine stress responses.
* Fever or acute illness/infection on day of experiment
* Pregnant or currently breastfeeding
* Prior experience with self-compassion training or compassion interventions, or prior experience with formal mindfulness or meditation training.