Stress eating causes more weight gain than stress-free snacking

A new study warns that eating while stressed may cause you to gain more weight than eating the same amount of calories in the absence of stress. The effect was linked to a molecular pathway in the brain that was controlled by insulin, according to the study, underscoring the importance of avoiding food as a way to deal with stress and negative emotions.

The idea of comfort food is nothing new — someone who is stressed may eat as a form of therapy against that stressful situation, but doing so may have a more severe effect in terms of weight gain. Researchers with Gavin Institute of Medical Research detailed the findings in a newly published study.

The study reveals that mice under chronic stress developed obesity faster than stress-free mice even though both ate the same high-fat food. A molecule called NPY may be the cause — it is naturally produced by the brain as a stress response, and it stimulates eating in both mice and humans.

The study's lead author Dr. Kenny Chi Kin Ip explained:

We discovered that when we switched off the production of NPY in the amygdala weight gain was reduced. Without NPY, the weight gain on a high-fat diet with stress was the same as weight gain in the stress-free environment. This shows a clear link between stress, obesity and NPY.

At the heart of the entire issue may be the hormone insulin, which is produced after eating a meal as a way for the body to absorb blood glucose and trigger a 'stop eating' process in the brain. Stress that causes a person to overeat results in chronically high insulin levels, which cause nerve cells in the amygdala to become desensitized to insulin.

Once that happens, the cells stop detecting insulin, causing NPY levels to rise, leading to both increased eating and increased weight gain from that food. It becomes a vicious cycle that may be difficult for someone to break, particularly if they're unable to remove themselves from the stressful environment.