Study Links Weight Stigma and Inflammation Part 1 - Authors and Methodology

The Acute Inflammatory Effects of Weight Stigma: An Experimental Pilot Study

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A number of you have asked me to write about today’s study. I think folks likely saw it on the social media accounts of the Association for Weight and Size Inclusive Medicine (AWSIM), they are an incredible organization doing important work and I highly recommend joining and following them!

I write and speak frequently about the ways in which the impacts of weight stigma overlap with the claimed impacts of existing in a higher-weight body. such that when people talk about “weight-related” or “ob*sity-related” health conditions, they may in fact be talking about weight-stigma related health conditions. (A similar issue exists for weight cycling and healthcare inequalities.)

A new study in this vein has come out that looks at the link between weight stigma and inflammation. The study is called The Acute Inflammatory Effects of Weight Stigma: An Experimental Pilot Study and it was published in August, 2025. In part 1 we’ll look at the study authors and the methodology, and in part 2 we’ll look at the results.

As I’ve mentioned before, I’m just as susceptible to confirmation bias as anyone else and one of the ways I control for that is to always seek to be as thorough for research around weight stigma or other topics that support weight-inclusive health as I am for research around, say, weight loss drugs so, as always, we’ll start with a thorough review of the authors

Also, when analyzing weight stigma research, we have to be on the lookout for co-option of anti-weight-stigma concepts. There is a movement that seeks to co-opt decades of anti-weight stigma work by fat activists and weight-inclusive health advocates in order to create a (weight loss industry friendly) definition of weight stigma that allows for the continuation of pathologizing higher-weight people and calling for their eradication. (ie: “we don’t want fat* people to be treated badly, but we do want to call fatness a problem and seek to eradicate fatness and prevent it from existing” which is, obviously, not an anti-weight stigma stance.) I’ve written about this in detail previously. Beyond the people doing this intentionally, there are also people making these mistakes from a place of implicit bias.

Summary

A group of authors ranging from self-described as weight-inclusive, to specifically weight-centric, to taking money from Weight Watchers and Novo Nordisk created a small pilot study to see if weight stigma was independently linked to acute inflammation. In the study 44 cis women were asked to perform a task, split into a group in which the task involved weight stigma and a group in which the task did not to see if experiencing weight stigma increased acute inflammation (measured via blood draw), which can, in turn, drive cardiometabolic disease.

Deeper Dive

This study did not offer disclosures, but they did include descriptions of the researchers body shape/size:

With respect to body shape/size, three of average build, two slender, one thinner, one athletic, one plus-sized, one mid-sized, one curvy with excess weight, and one lean.

People are allowed to describe themselves however they choose. I do notice that there was no use of “fat” among the descriptions of higher-weight bodies and the use of “excess weight” is, in and of itself, a stigmatizing idea about size. I say this not to question or shame the person who described themselves that way (again, that is their right) but to contextualize the author’s possible approach to weight stigma and the existence of higher-weight people.

Again, there weren’t any disclosures but I did, as always, research the authors individually (this is always a tedious process so extra shout out and thanks to my paid subscribers who make this time-consuming work possible!)

Note, I want to always include author information for the record but if you’d rather skip it feel free to scroll down to the heading that says Methodology.

Throughout, I will follow my standard process of adding asterisks to ob*sity and overw*ight as explained at the end of the piece. That said, I also want to point out that sometimes compromises are made by researchers in order to get work published (for example, the use of stigmatizing terms like “ob*sity” and “excess weight”) so while they are things that always get my notice and can be a red flag, the use of this language isn’t automatically proof that someone is coming from an anti-fat or anti-weight-stigma co-opting perspective.

Natalie G Keirns

Her bio at Ball State, where she is a professor of public health states

“In graduate school, she served as PI on a National Institutes of Health predoctoral fellowship and as lead interventionist and trial coordinator for two NIH-funded behavioral weight loss trials. Through these activities, she earned a plethora of (i.e., 16) research-related awards and has published 24 peer-reviewed research articles to date. Dr. Keirns’ current research program is focused on reducing the public health burden of cardiovascular disease (CVD) by identifying and intervening on mechanisms by which psychosocial factors contribute to CVD development in people with ob*sity.”

The good news here is that her current research seeks to intervene on mechanisms by which psychosocial factors contribute to cardiovascular disease in higher-weight people (hopefully rather than attempting to intervene on body size!) I do note the choice to use of weight-loss industry (stigmatizing) “person first” language.

Bryant H Keirns

His bio at Ball State where he is Assistant Professor of Nutrition and Dietetics and Graduate Program Director of Nutrition and Dietetics states:

Dr. Keirns’ research explores cardiovascular disease risk of novel ob*sity phenotypes and how poor gut health may impact cardiovascular health. He plans to continue to study normal-weight and metabolically healthy ob*sity and, more generally, the relationship between diet and lifestyle factors, gut health, and cardiovascular disease.

A lot of his research is rooted in something called “normal weight ob*sity” which his research defines as “those with a normal body mass index (BMI) and high body fat percent.” My concern here is that the healthcare system’s choice to cleave to the construct of “ob*sity” creates concepts (that the weight loss industry manipulates for profit) that create additional stigma and harm to higher-weight people. The main issue with this is that instead of being clear that there are people of all sizes with health issues and various percentages of adipose tissue, the use of the construct of “ob*sity” continues to stigmatize higher-weight people, even when they aren’t even the ones being studied.

Cindy E Tsotsoros

Her bio at the University of Rhode Island where she is an Assistant Professor of Human Development and Family Science does not mention weight and says

“Her program of research strongly focuses on aging in the neurological, developmental, and psychophysiological correlates of cognition”

Her research list finds research on so-called “normal weight ob*sity” as well as some work around “ob*sity” and “excess weight”

Harley M Layman

Her Research gate profile explains

I am a T32 postdoctoral fellow at WashU in St. Louis. I graduated with my PhD in Clinical Psychology in 2025. My research interests include investigating the relationship between mental and physical factors related to body image disturbance. Specifically, I am interested in examining how the internalization of and drive for different body ideals are associated with different eating and exercise, psychological factors (e.g., ACEs), and physiological and neurocognitive consequences.

Her research list also shows some research around “ob*sity” and “excess weight”

Madison E Stout

Her bio at the University of Evansville where she is an Assistant Professor of Clinical Psychology states:

Dr. Stout’s program of research aims to, 1. examine and understand the neurocognitive and neuroendocrine systems through which loneliness relates to poor health, and 2. develop and test treatment programs to reduce or prevent loneliness, facilitate healthy interpersonal relationships, and reduce health risk. To this end, she has conducted multiple research studies investigating each aim. Most recently, she received a competitive pilot award from the Society of Behavioral Medicine (SBM) to assess the effectiveness of mental health treatment, as currently delivered in the VA, at reducing loneliness in Veterans seeking mental health care. In addition to loneliness, Dr. Stout’s research has focused on adverse childhood experiences (ACEs), stigma, and chronic stress.

Her research list includes a couple of studies around “ob*sity” and also a study that uses the less stigmatizing “high weight.”

Christina M Sciarrillo

Her bio at Penn State where she is an Assistant Research Professor states

I study how diet and nutrition influence the regulation of body weight, energy intake, metabolism, and cardiometabolic disease risk.

Her research list also includes some work around “ob*sity” and “excess weight”

Sam R Emerson

His bio at Oklahoma State University where he is an Associate Professor of Nutrition Sciences says nothing about weight

My research is focused on the impact of nutrition and physical activity on cardiometabolic health in humans. I have a specific area of interest in assessment of cardiometabolic risk factors and how lifestyle behaviors (e.g. diet and physical activity) modify these risk factors. We regularly utilize acute feeding challenges as a sensitive assessment of metabolic health and to delineate differences based on diet, physical activity level, age, sex, and body composition.

As a part of my research program, I have helped guide the development of the Laboratory for Applied Nutrition and Exercise Science (LANES). LANES is a Nutritional Sciences lab housed in the College of Education and Human Sciences. LANES is a space designed for clinical research with humans, usually in the context of nutrition and exercise science. The space contains several metabolic analyzers, treadmills, cycle ergometers, a metabolic cart (for exercise and resting metabolic rate testing), and a Doppler ultrasound

His research list includes a number of studies mentioning “ob*sity” and so-called “normal weight ob*sity”

Jennifer Byrd-Craven

Her bio at Oklahoma State University where she is a professor of psychology states;

My research primarily examines the neuroendocrine underpinnings of human social behavior. My lab focuses on a variety of understudied relationships, including female friendships and paternal investment. We employ interdisciplinary methods to uncover the interplay between social context and neuroendocrine responses.

Research Interests:

Broad: Behavioral Endocrinology; Psychobiology of the Stress Response; Sex Differences in Stress Responses and Social Cognition; Evolutionary Psychology

Specific: Psychosocial factors related to plasticity in the stress response system, th timing of life history traits, female sociality, and peer relationships.

Her research list doesn’t include any mention of “ob*sity”

Jaimie Arona Krems

Her lab at UCLA where she is an Associate Professor with a primary area of Social Psychology and a secondary area of Social and Affective Neuroscience is described

We’re a social psychology lab. Our research draws on interdisciplinary theoretical perspectives—from social psychology, cognitive science, + evolutionary anthropology, animal behavior, relationship science—to investigate how people’s social minds both create + navigate our social worlds.

Her research list includes a mention of “excess weight” but also of the less stigmatizing “high weight.”

Rebecca L Pearl

If this name seems familiar it is because we’ve discussed her before. She wrote some of the research with what I would characterize as dubious claims about weight loss attempts not creating eating disorders, in which we learned that she had received grant funding from Weight Watchers, and has consulted for Weight Watchers and Novo Nordisk.

She is an Associate Professor in the Department of Clinical and Health Psychology in the College of Public Health and Health Professions at the University of Florida.

She runs the “Body Image and Stigma Lab” though the name of this lab is, from my perspective, misleading. Their work is concerning in that there is a focus on internalized weight stigma while preserving the pathologization of higher-weight bodies which is what, in many ways, is driving the internalized weight stigma (for example, being concerned that weight stigma might make people less “successful” at “weight management”) A focus on the idea of internalized weight stigma (especially when paired with researchers who pathologize higher-weight bodies) can also, purposefully or inadvertently, shift the blame from the entity creating the weight stigma to the higher-weight person for having internalized it which creates additional stigma through victim blaming.

In addition to research, they publish in public media outlets. Recent articles include:
“Weight stigma isn’t just cruel – it makes losing weight harder” for CNN and “A new kind of weight loss approach helps people deal with self-loathing instead of just ignoring it.”

Not all of their research and publications make the mistake of reinforcing anti-fatness while claiming to want to reduce weight stigma, but a significant portion of them do and that, in addition to the weight loss industry funding, is a big concern for me.

A Janet Tomiyama

If this name looks familiar, it’s because I frequently refer to her work around the claims about the supposed health benefits of 5-10% weight loss. Her faculty page at UCLA where she is Professor in Health and Social Psychology states

Research and Teaching Interests

Eating behavior, stress, ob*sity, dieting, comfort eating, weight stigma, health disparities, health behaviors

She runs the Diet, Stigma, and Health (DiSH) lab at UCLA. Her bio there explains:

Dr. A. Janet Tomiyama, Ph.D., is a UCLA psychology professor whose research is redefining how we think about health, weight, and well-being. As Director of the Diet, Stigma, and Health (DiSH) Lab, she investigates the hidden costs of dieting, the science of comfort eating, and the real-world impact of weight stigma. Her groundbreaking work has been instrumental in reframing how we think of our bodies, both personally and clinically, and has begun to change entrenched practices at the doctor/patient level regarding the problematic use of BMI as a default diagnostic. She was among the first to show that fat shaming harms people’s biology as well as their feelings, upending specious arguments about “tough love” and shifting the conversation from blame to compassion. Her research has catalyzed a paradigm shift in public health, challenging long-held assumptions about weight and wellness and inspiring more humane, evidence-based approaches to care. Her work has been featured in The New York Times, USA Today, NPR, BBC News, and even The Onion, and she’s received over $4 million in research funding from the National Institutes of Health and the National Science Foundation. A recipient of the prestigious Janet Taylor Spence Award for Transformative Early Career Contributions from the Association for Psychological Science, Dr. Tomiyama brings a fresh, evidence-based perspective to some of the most emotionally charged issues in public health. She is a sought-after speaker, an award-winning teacher and mentor, and a passionate advocate for weight-inclusive health policy. She is also a scientific leader, and is President of the Society for Biopsychosocial Science and Medicine. Her speaking engagements blend scientific rigor with a clear, compassionate voice, making her a trusted guide for anyone who’s ever felt that their body was a problem to solve.

Misty AW Hawkins

She is an adjunct professor at Indiana University Bloomington and her work is very specifically focused on body size manipulation, including viewing simply existing in a higher-weight body as a disease.

An associate professor in the Department of Health and Wellness Design, Misty Hawkins is a clinical health psychologist and behavioral medicine researcher on a mission to understand the relationships between cognitive factors (e.g., executive function), emotional factors (e.g. depression), chronic diseases (e.g., ob*sity, cardiovascular disease) and health behaviors (e.g., eating, exercise) as they exist in and are impacted by larger socioeconomic contexts.

She received a K23 Career Development Award from NIDDK to examine cognitive factors related to behavioral weight loss interventions and was a research project leader on a project examining neurotrophic factors related to early life adversity and ob*sity funded by the National Institute of General Medical Sciences. She has a thriving partnership with Cherokee Nation in Tahlequah, Oklahoma, to examine behavioral weight loss interventions in Indigenous populations and completed a funded pilot of acceptance-based weight loss therapy in collaboration with the Oklahoma Shared Clinical and Translational Research center.

As a first-generation college student herself, Hawkins has a commitment to mentoring trainees from under-represented and disadvantaged background and has helped her mentees secure NIH funding for their dissertation work.

Areas of Expertise

Ob*sity, neurocognition, alimentation, behavioral weight loss, clinical trials, biomarkers, inflammation, glucoregulatory function, excess adiposity.

So those are the authors. They run the gamut from weight-inclusive, to specifically weight-centric, to taking money from the weight loss industry. None of that would invalidate any study findings, but I think its’ always helpful to clarify and contextualize.

Methodology

They begin by explaining:

Weight stigma is a chronic stressor and may contribute to cardiometabolic health risk. This pilot study tests an experimental protocol exploring acute inflammation as a potential biological mechanism connecting weight stigma and disease risk. Preliminary effect sizes and protocol feasibility were assessed.

The idea here is that the stress of experiencing weight stigma may independently create health risks. Cardiometabolic health risk can be driven by inflammation. So this study tested to see if weight stigma was linked with acute inflammation (which is to say if inflammation increased immediately upon experiencing weight stigma.)

This was a pilot study which means that it is a small study and that no strong generalizable conclusions can really be drawn, but pilot studies are an important step to larger research.

They begin:

Weight stigma, an emerging chronic stressor, is independently linked to adverse health outcomes such as cardiometabolic disease (Puhl et al., 2020; Udo & Grilo, 2017).

This is an important point. The link is independent which, again, should create questions in assumptions about weight itself causing these adverse health outcomes that are also linked to weight stigma.

The Cyclic Ob*sity/Weight-Based Stigma (COBWEBS) model provides a unified theory of how experiencing weight stigma contributes to poor health via the physiological stress response, namely chronic cortisol elevation (Tomiyama, 2014).

I have some issues with COBWEBS both in general and as these researchers have described it here. The cited piece they cited about COBWEBS explains:

This model characterizes weight stigma as a “vicious cycle” – a positive feedback loop wherein weight stigma begets weight gain. This happens through increased eating behavior and increased cortisol secretion governed by behavioral, emotional, and physiological mechanisms, which are theorized to ultimately result in weight gain and difficulty of weight loss.

If they were claiming that this is a viscous cycle because, while there is nothing wrong with being fat* or becoming fatter, weight stigma leads to weight gain and being higher-weight leads to additional weight stigma and thus we have to focus efforts on reducing weight stigma, I would absolutely agree. Unfortunately, I don’t think that is what it’s saying.

Here’s the thing, the characterization of this as a “vicious cycle” here seems to be suggesting that weight stigma is bad because it makes people fatter and/or makes them less likely to become thin. The idea that being higher-weight/becoming higher-weight is a bad thing is, in and of itself, weight stigma. In fact I would suggest that it is, if not the root, at least a major root of weight stigma.

I also don’t think that this is “a unified theory” explaining how weight stigma contributes to poor health. COBWEBS is extremely focused on weight gain rather than focusing on more direct links between weight stigma and health issues (as are tested in this pilot study.)

The cited piece about COBWEBS also contains this bit of clear weight stigma (with an extra content warning ):

Given the high prevalence of overw*ight and ob*sity in this nation, the processes governing weight stigma have the potential to affect millions of Americans. If theoretical predictions from the COBWEBS model are substantiated by future research, we may then have further understanding of why ob*sity remains such an intractable problem: ob*sity stigma begets increased eating and fat deposition, and is therefore a hurdle to weight loss.

Yikes. You cannot describe the existence of a group of people who share a single physical characteristic (being higher-weight) as an “intractable problem” without stigmatizing them. I’m concerned that the vicious cycle is this: making the reduction/eradication of higher-weight people the focus of weight stigma research thus creating weight stigma research creates more weight stigma.

If you really want to understand the vicious cycle of weight stigma, I recommend Rachel Fox’s Misdiagnosing Fat Oppression: Weight Stigma and the Anti-Ob*sity Assemblage

Back to the original study which continues

Indeed, everyday weight stigma is associated with elevated basal cortisol, and studies have shown altered cortisol reactivity following in-lab exposure to weight stigma stress (Puhl et al., 2020). Importantly, these physiological effects of weight stigma are independent of adiposity (Puhl et al., 2020). Chronic stress has also been linked to systemic chronic inflammation, which is observed in numerous cardiometabolic diseases (Furman et al., 2019; Rohleder, 2014). Given the known interrelationships between stress, cardiometabolic disease, and ob*sity (Ippoliti et al., 2013), inflammation is a strong candidate for mediating weight stigma stress and disease risk.

I want to state again how important this is. The issue they are studying is whether weight stigma creates inflammation that, in turn, independently drives disease risk. (For more on claims about weight and inflammation, Dr. Zed Zha and I wrote a 4-piece series about it that you can find here.)

The study continues:

The current pilot study tests an in-lab protocol with repeated blood draws via peripheral intravenous catheter (PIVC) designed to explore acute inflammation as a potential biological mechanism by which experiencing weight stigma may contribute to disease risk. If feasible, a PIVC-based protocol would allow for observation of dynamic biological responses, contributing to our understanding of acute physiological reactions to weight stigma stress and potential mechanisms in cardiometabolic disease risk. The goal of this experimental stress reactivity study was to assess acute inflammatory changes serially over 90 minutes in a sample of adult women with excess weight. Protocol feasibility and preliminary effect sizes were assessed.

So this study tested the impact of weight stigma on inflammation by testing inflammation markers in the blood during a specific, lab-created experience of weight stigma.

Concerning here, from a stigma point of view. is the description of the subjects of being women with “excess weight” which is a stigmatizing way to describe someone, since “excess weight” describes a body as being “wrong” rather than using an affirming description of the body as part of the natural diversity of body sizes.

Participants

Participants (N=44) were adult women with overw*ight/ob*sity who were enrolled in an ongoing parent study (NCT04076722). Due to the nature of the parent study, half of participants had a history of high (3+) adverse childhood experiences, including abuse, neglect, and/or household dysfunction (Felitti et al., 1998). Key eligibility criteria included: 1) BMI≥25 kg/m2, 2) non-smoking, 3) no presence of acute infection/autoimmune disorder, 4) no recent (<48 hours) use of NSAID medications/not taking immunosuppressive medications, and 5) no significant medical or psychiatric comorbidities (Table S1).

This was a small study as we discussed before. Their use of weight-loss industry driven (stigmatizing) person-first language is concerning here but, again, it’s possible that this is a compromise the researchers made for publication.

In part 2 we’ll look at the results!

This month’s online workshop is happening tonight: Weight-Neutral Joint Pain Management with sports medicine physicians Dr. Julia Bruene and Dr. Jeremy Alland. There is a pay-what-you-can-afford option and a video will be sent to all registrants.
Details and registration here!

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*Note on language: I use “fat” as a neutral descriptor as used by the fat activist community, I use “ob*se” and “overw*ight” to acknowledge that these are terms that were created to medicalize and pathologize fat bodies, with roots in racism and specifically anti-Blackness. Please read Sabrina Strings’ Fearing the Black Body – the Racial Origins of Fat Phobia and Da’Shaun Harrison’s Belly of the Beast: The Politics of Anti-Fatness as Anti-Blackness for more on this.