Stress correlates with higher levels of obesity.

Truncal obesity

Earlier I wrote an article about the hormone cortisol and why it is the enemy of a slim waistline.  Chronic cortisol exposure or elevations have long been hypothesized to contribute to obesity.  You do not have to look any further than symptoms of Cushing’s syndrome to see that elevated cortisol level should cause obesity.  Cushinoid patients have truncal obesity and elevated blood sugar both of which are risk factors for metabolic syndrome and heart disease.  Although there is limited research to back the theory that stress can induce obesity in humans, exposure to higher levels of cortisol should promote obesity.  

A new study, published in the journal Obesity, appears to support this theory[1].  In the study, researchers showed that exposure to higher levels of cortisol over several months is associated with people being overweight.  This study examined associations between hair cortisol concentrations, an indicator of long‐term cortisol exposure, and adiposity in a large population.  Data were from over 2,5oo men and women aged 54 and older participating in the English Longitudinal Study of Ageing.  Hair cortisol concentrations were determined from the scalp hair.   Height, weight, and waist circumference were also measured.   The researchers found that hair cortisol concentrations correlated with weight and waist circumference.  Cortisol was significantly elevated in participants with obesity and raised waist circumference.  

There were limitations to the study, which included the fact the data was from an older population in which levels of cortisol may differ relative to younger adults and the sample was almost exclusively white. It is not currently known whether chronically elevated cortisol levels are a cause or a consequence of obesity.

The study is an observational study so causation cannot be determined.  More research is needed.  The study is limited by the lack of diversity of the test population.  

The bottom line:  Long-term or chronic exposure to elevated cortisol is associated with markers of adiposity and with the persistence of obesity over time.  This result is not surprising and it makes physiologic sense.  More research is needed to determine causation.