Adolescence is a period defined by rapid physical, emotional, and social change, and for many young people, it is also shaped by body image issues and weight stigma. Those experiences, researchers say, can drive chronic stress with long-term health consequences.
Research from Indiana University reveals how weight-based stigma becomes biologically embedded in individuals, contributing to what scientists call allostatic load, the cumulative physiological wear and tear caused by chronic stress.
Assistant Professor of Anthropology Jennifer Cullin
"During childhood and adolescence, young people are forming their sense of identity," said Jennifer Cullin, an assistant professor of Anthropology in the College of Arts and Sciences at IU Bloomington. "They're learning about themselves, noticing what others think of them, and realizing that not everyone sees them the same way. How others treat them, positively or negatively, can have a powerful impact."
This is where identity threat can take root. As a biological anthropologist and human biologist, Cullin explores how social bias, especially around body weight, shapes a society's ideas of what a "normal" body is, and how those pressures translate into real biological stress, as well as health gaps, among youth.
"If people aren't valuing you, there's a risk of internalizing that, thinking negatively about yourself or even endorsing stigmatizing ideas," Cullin explained.
The effects extend far beyond self-esteem. Constant teasing, bullying, or judgment can activate the body's stress-response system. "Those hormones are meant to help in moments of real danger," Cullin said. "But with psychosocial stress, the energy is released without any real threat to escape from. Over time, that chronic activation can accumulate and impact long-term health."
Cullin's recent study published in Social Science & Medicine, "Fat shame does not promote health," documents links between weight-based teasing and elevated blood pressure, increased inflammation, and disrupted eating behaviors among U.S. youth.
Early Curiosity, and a Path to Anthropology
A first-generation college student, Cullin entered school undeclared, hoping that general education courses would help her discover the right fit.
Anthropology quickly caught her attention. "I knew it was the study of people, and I was always interested in ancient Egypt, mummies, archaeology," she said. Childhood road trips to archaeological sites, a fascination with true crime shows like Unsolved Mysteries, and her habit of wandering through old cemeteries all nudged her toward the field.
As an undergraduate, Cullin explored all corners of anthropology but found herself drawn most strongly to biological anthropology: the study of human social behavior and biology. During her master's program, she began considering how the field intersects with public health. By the time she entered her PhD, her focus sharpened: she wanted to understand how negative social experiences, stigma, bullying, and teasing become embodied, influencing health long after adolescence.
Cullin concentrated specifically on fat stigma and weight-related teasing among young people, tracing their effects from adolescence into early adulthood.
What the Research Shows
In partnership with Provost Professor of Anthropology Andrea Wiley, Cullin has helped develop a new framework for understanding variation in human health outcomes, known as biological normalcy. In a previous study, Wiley and Cullin use this framework to examine how people define what is considered "normal" or "abnormal" in biological traits. In Cullin's research, the trait of focus was body fat.
In a 2023 Indiana youth study published in the American Journal of Biological Anthropology, Cullin recruited 175 IU undergraduate students from 38 counties to participate. Fat stigma was measured using a survey, and overall stress on the body was estimated using health indicators related to the heart, metabolism, and immune system.
Her work challenges the common belief that shame improves health, showing instead that stigma itself may be harmful. Notably, youth who reported frequent fat stigma had poorer health outcomes later in life, even after accounting for their actual body fat. However, context mattered.
"The strongest effects appeared in communities where obesity was uncommon," Cullin noted. "In places where larger bodies were more typical, the relationship between stigma and poor health was minimal. But in areas where obesity was less common, experiencing stigma predicted the worst health outcomes."
The takeaway? Biology and culture interact powerfully, shaping how young people interpret their bodies and how their bodies respond to stress.
Cullin argues that several pervasive cultural beliefs about weight are not supported by evidence:
- Fat is always dangerous. Not true: many people with high body fat are metabolically healthy, while some thin individuals are not.
- Fat shame motivates weight loss. Research shows the opposite. Stigma predicts weight gain, disordered eating, and stress.
- Weight is purely a matter of willpower. Genetics, environment, stress, and social factors all play major roles in determining weight.
"No long-term study has shown that any diet reliably helps people lose weight and keep it off," Cullin said. "And yet we continue to treat weight as a personal responsibility issue rather than a complex biological and social phenomenon."
Childhood and adolescence are defining periods for identity development. Negative treatment based on weight can induce identity threat, fuel internalized stigma, and trigger chronic stress, processes known to damage long-term health.
Cullin recalls her own formative experience: as a teenager, relatives assumed she had an eating disorder because she was thin. "It changed how I behaved for years," she said. But fat stigma proves even more detrimental. Later, anthropology research helped her understand that thinness and fatness are not treated equally. Thinness is often celebrated; fatness is stigmatized.
That stigma, research shows, harms health and should never be used in health initiatives to try to change behavior.
