You might already know that stress has a direct impact on appetite, food preferences, and perhaps even body weight. But do you know why stress has that affect?

Acute stress

If you experience an acutely stressful event, then you might notice you can actually lose your appetite and even lose a little weight. This is because acute stress triggers a release of the hormone known as norepinephrine, which is one of the chemicals in your body responsible for the so-called “fight or flight” response. 

Acute stress also slows down a chemical messenger in the body known as neuropeptide Y (NPY). The combined effect of having higher norepinephrine and lower neuropeptide Y is decreased hunger and revved up metabolism. 

Chronic stress 

However, when stress becomes chronic, it triggers quite a different hormonal cascade. When you experience long-term stress from any cause – internal or external – your adrenal glands are being repeatedly prompted to release a hormone known as cortisol.

Normally, it’s the secretion of cortisol by the adrenal glands that helps us adapt to a stressful situation.

Therefore, it’s important for your health that your adrenal glands do produce cortisol in response to stress. It is equally important, however, that your cortisol level returns to normal after the stressful event has passed. 

While it is not always the case, one common pattern that occurs in chronic stress is that cortisol levels become persistently elevated. If your stress response is activated too often, then your body doesn’t have a chance to return itself to normal.

Cortisol is a powerful hormone, and it has wide-ranging impacts in the body, including powerful effects on your reproductive, immune, and endocrine systems. And the impacts of cortisol can be exaggerated by stress that does not let up. 

Among other things, persistently elevated levels of cortisol can alter hunger and metabolism.

Cortisol does this by triggering an increase in another hormone – insulin. Having a higher insulin level in your body triggers your body to store more calories as fat (especially around your middle).

Higher cortisol and insulin levels also cause blood sugar levels to be more irregular, which can trigger hunger and food cravings, especially for sugary foods that raise blood sugar and give you short-term energy. 

Does this sound like you?

If it does, then you are not alone! According to a 2017 survey published by the American Psychological Association, three out of four U.S. adults had at least one symptom of acute stress during the previous 30-day period, and two out of five had symptoms of chronic stress, such as sleeplessness, irritable or anxious mood, or fatigue.1

Multiple studies have now associated chronic stress with weight gain and higher body mass index (BMI).2

And now you know why – it’s a result of persistently elevated levels of cortisol and insulin caused by chronic stress.

If you want to gain a better understanding of the connection between your stress level and your weight, then you can use a Thorne at-home test  to give you insights into not only how your cortisol level changes during the day, but other personalized insights on your weight, such as your thyroid hormones and blood sugar. 


Thorne released a series of podcasts between Dr. Jacqueline Jacques and Dr. Alan Miller that discuss a range of topics about weight management. This 5-part series answers common questions and provides guidance on diet, nutrition, and lifestyle choices.

The five podcasts are:

1. Diet. This podcast sorts out the myths from the facts, , and focuses on the best-studied dietary principles to support healthy weight and overall well-being.

2. Exercise. This podcast addresses the role of exercise in weight loss and weight maintenance. It explains how to get started, what types of exercise to consider, for what duration, and how often.

3. Lifestyle. This podcast focuses on the four s’s: sleep, stress, sugar, and sedentary lifestyle. These four factors are inter-related and each one plays a role in weight control and metabolism

4. Supplementation. This podcast focuses on key areas where supplementation supports weight management  and explains several of the recommendations in the Thorne Weight Management Program.

5. Q & A with Dr J. In this podcast, Dr. Miller asks Dr. Jacques to answer real questions from Thorne customers  who ask about weight management and the Thorne Weight Management Program. They also address common themes frequently asked about.

If you are having weight management issues and you want to know why, then take the Thorne Weight Management Test – a simple saliva and finger-prick blood test that looks at multiple biomarkers that could be contributing to your weight woes.

Thorne’s Weight Management Test will tell you about your:

  • Thyroid function – TSH
  • Carbohydrate metabolism – insulin and HbA1c
  • Stress hormones – cortisol and DHEA
  • Sex hormones – estrogen, progesterone, testosterone
  • Vitamin D