Weight stigma, not weight, has the biggest effect on mental health after BMS

Weight stigma - and not weight itself - has the biggest impact on mental health and healthy behaviours in the years after bariatric and metabolic surgery (BMS), according to researchers from the University of Utah Health Sciences (U of U Health). They found that patients who had gone through BMS tended to experience much less weight stigma, and that this reduction in weight stigma - but not lower BMI - was associated with healthier eating habits and better mental health.

On the other hand, continuing to experience stigma after surgery was associated with higher risks of depression, anxiety, and disordered eating.

"We think of a lot of health issues for these patients as being a given," explained Dr Larissa McGarrity, the first author on the study and a clinical psychologist in physical medicine and rehabilitation at U of U Health. "But the cumulative effect of stigma and discrimination actually contributes to a large part of the physical and mental health problems that we disproportionately see for patients with obesity compared to the general population."

People tend to experience significantly lower levels of weight stigma - shame, blame, and guilt around their body weight or shape - in the years following surgery, the researchers found in a survey of nearly 150 people.

McGarrity, who is also an associate professor in the Spencer Fox Eccles School of Medicine at the University of Utah, said that the change in experienced weight stigma was striking.

"The degree of change far exceeded clinically established norms in terms of what's meaningful for a patient's life and the impact they would notice," she added.

This reduction in weight stigma was linked to notable improvements in both mental and physical health. Previous research has established that the chronic stress of weight stigma directly contributes to many of the health risks associated with obesity and people who experienced less stigma in the years following BMS had lower levels of anxiety and depression.

They were also less at risk for disordered eating, such as binge eating. People who experienced less weight stigma were more likely to lose more weight and maintain the loss.

Importantly, McGarrity noted, weight loss itself was not associated with these positive changes to health. Change in BMI did not correlate with depression, anxiety, or dysregulated eating - implying that social factors, rather than innate biological ones, make a huge contribution to the mental and physical health of people with obesity.

However, not every patient who went through weight loss surgery experienced a decrease in bias and stigma. For about 40% of patients, weight stigma continued to impact their quality of life, leading to increased risk of mental health concerns, disordered eating, and weight recurrence.

Since the survey targeted patients who were treated at U of U Health, future research will be needed to test whether the results hold true in broader populations. The researchers say their work emphasises the critical need to reduce weight stigma, both within health care settings and without.

"The wide-ranging effects of weight stigma are one of the most important things I'm thinking about from both a research and clinical perspective," McGarrity concluded. "Weight loss is helpful for a whole lot of things, but that change in weight stigma may actually be the more powerful thing for mental health and quality of life over time."

The findings were featured in the paper, ‘Weight Stigma and Bariatric Surgery: Prospective Improvements, Psychological Health, and Weight’, published in the journal Health Psychology. To access this paper, please click here (log-in maybe required)