Stress and Weight Gain: What’s the Connection?


Many people have had a personal experience of recognizing that stress has an impact on appetite, food preferences, and perhaps body weight. But have you ever stopped to wonder why?

Acute stress.

If you have an acute stress, you may notice that you actually lose your appetite and may even lose a little weight. This is because acute stress triggers a release of the hormone norepinephrine (NE), one of the chemicals in your body responsible for the “fight or flight” response. Acute stress also inhibits a chemical messenger in your body called Neuropeptide Y (NPY). The combined effect of higher NE and lower NPY is decreased hunger and revved up metabolism.

Chronic stress.

When stress becomes chronic, however, it sets quite a different hormonal stage. If you experience long-term stress from any cause – internal or external - your adrenals can be repeatedly triggered to release the hormone cortisol. Normally, it’s the adrenal glands and their secretion of cortisol that helps us adapt to normally to the situation. It is important for your health that your adrenal glands produce cortisol in response to stress. However, it is equally important that those levels then return to normal when the event has passed.

While not always the case, one common pattern seen in chronic stress is that cortisol can become persistently elevated above the normal baseline. If your stress response is activated too often, then your body doesn’t have a chance to return to normal. Cortisol has wide-ranging impact in the body including effects the reproductive, immune, and endocrine systems – and these effects can be exaggerated by stress that does not let up.

Among other things, this excess cortisol can alter hunger and metabolism. It does this by triggering an increase in another hormone – insulin. Higher insulin levels trigger your body to store more calories as fat (especially around your middle). They also cause blood sugar levels to be more irregular which can trigger hunger and cravings (especially for sugary foods that raise blood sugar and give you short-term energy).

Does this sound like you?

If it does you are not alone! According to a 2017 survey published by the American Psychological Association 75 percent of people had at least one symptom of acute stress in the prior month and 35-45 percent had symptoms of chronic stress such as sleeplessness related to thoughts keeping them awake, irritable or anxious mood, or fatigue. (1) Multiple studies have associated chronic stress with weight gain and higher body mass index (BMI). (2)  While managing stress alone is not proven as a treatment for weight loss, it may be an important underlying driver of behavior that can be addressed through appropriate care.





  • (accessed Jan 30, 2019)
  • Block J, He Y, Zaslavsky A, et al. Psychosocial stress and change in weight among US adults. Am J Epidemiol. 2009;170(2):181-92.