A new study was recently published addressing stress and eating disorders. This study was unique in that it had the controlled variables of a residential setting. Both clients and clinicians perceive on some level that binge eating symptoms often come as a result of stress. This study highlights the contrary. These “hot off the press” findings came out last month in the Journal of Neuroscience.
While not a blanket statement, we often imagine restricting comes from taking control and bingeing, compulsive eating and purging relate to stress and loss of control. This theory, however, has not been formally tested until now. The research considers what someone with an eating disorder may or may not do with food under stress.
To study this more closely, a team at the University of Cambridge over in the UK came together. They invited 85 women; 22 with anorexia, 33 with bulimia and 30 controls (those without an eating disorder) to attend a 2 day stay at a research facility. Being in this environment, researchers were able to control for several things like the room itself, the food and other important factors.
Every day, clients received specific foods chosen by a dietitian. They then fasted (or didn’t eat for a few hours) and then were given a brain scan. During the scan, clients were asked to perform computer tasks assigned to elicit “stress”. They then were provided access to an “all you can eat” buffet environment. Participants were told they could eat as much or as little as they wanted. The following day, they were not exposed to the stressful environment and told to do the same (eat whatever they wanted). What differences did they find?
The results showed that stress did not affect performance for either patient groups or the controls. Controls ate more in general but those with a diagnosed eating disorder did not change how they ate on either day. Even with brain scans showing proof of stressful responses! One of the physicians working on this study Dr. Westwater shared, “women with bulimia seem to have a problem slowing down to changes in the environment. This theory suggests these women should have eaten more, but that’s not actually what we found.”
In addition, the team took blood samples to study hormone levels in the blood. As hormones are affected by stress they found that those with anorexia, had an increase in ghrelin (a hunger hormone) and ALSO had an increase in peptide tyrosine (a fullness hormone). Confusing right?! This helps us understand better the internal struggle. The body is hearing two messages-one saying, “you’re hungry” but the other saying “you’re full”. Those with bulimia had no differences in these hormones but did have lower levels of the stress hormone cortisol than controls. It is found that those with chronic stress or depression have low levels of this measured hormone (Ovsyannykov, 2021).
In general, this new information helps to realize how complex disordered eating really is. Many assume stress is at the base of many eating issues, which simply may not be the case. This study does not mention the history of trauma or histories of the patients themselves which may be helpful to understand in the future. Any research such as this is helpful especially those with closed environments. Stay tuned for more research to come!
References:
Binge-Eating Not a Stress Response, Finds Eating Disorder Study | Technology Networks
Westwater ML, Mancini F, Gorka AX, et al. Prefrontal responses during proactive and reactive inhibition are differentially impacted by stress in anorexia and bulimia nervosa. J Neurosci. 2021. doi: 10.1523/JNEUROSCI.2853-20.2021