HealthDay News — Instead of motivating weight loss, exposure to bias because of weight may increase a person’s risk of becoming or remaining obese, researchers have found.
After adjusting for age, sex, ethnicity, education, and baseline BMI, those who reported weight discrimination were significantly more likely to become obese at follow-up (odds ratio 2.54; 95% CI: 1.58-4.08), Angelina R. Sutin, PhD, and Antonio Terracciano, PhD, from the Florida State University College of Medicine in Tallahassee reported in PLOS ONE.
Similarly, those who reported weight discrimination and were obese at baseline were significantly more likely to remain obese (OR 3.20, 95% CI: 2.06-4.97).
“Weight discrimination, which is often justified because it is thought to help encourage obese individuals to lose weight, can actually have the opposite effect: it is associated with the development and maintenance of obesity,” the researchers wrote. “Such discrimination is one social determinant of health that may contribute to inequities in employment, relationships, healthcare delivery, and body weight.”
They analyzed data from 6,157 community-dwelling residents of the United States aged 50 years and older (mean age 66.5, 58.6% female) who participated in the Health and Retirement Study, a nationally representative, longitudinal survey. Height and weight measurements were taken in 2006 and 2010 and participants were surveyed for experience with weight discrimination.
At baseline, 32% were obese (body mass index 30 kg/m2 or higher) and 8% said they experienced discrimination because of their weight. Of those who were not obese at baseline, 8.5% became obese within 4 years. And of those who already were obese at baseline, 86% remained so at follow-up.
The associations appeared to be specific to weight discrimination as other forms of discrimination, such as discrimination based on sex or race, were not significantly associated with obesity risk.
Several behavioral mechanisms, such as coping with discrimination through eating and avoiding exercise, are likely to contribute to the association, according to the researchers.
They also proposed several physiological mechanisms that could be involved.
“Psychological stress, particularly stress that involves heightened public awareness, engages the hypothalamic-pituitary-adrenal (HPA) axis and triggers cortisol release, and experimental administration of glucocorticoids has been found to increase food intake,” the researchers wrote. “Further, individuals with high cortisol reactivity tend to choose calorie-dense, high-fat foods following a social stress test.”
They added that the HPA axis is also involved int he release of endogenous opioids, which “stimulates intake of palatable foods, and palatable foods likewise encourage opioid release; a cycle may thus ensue that reinforces intake of high-fat, calorie-dense foods as a way to cope with stress.”
Study limitations included using a single-item measure to assess weight discrimination and lack of generalizability to younger populations. Also, the researchers did not examine potential underlying mechanisms.