The Stress Response and Weight: what you need to know to create effective protocols

Weight loss is an omnipresent topic amongst a variety of healthcare professionals. Yet, achieving weight homeostasis is often oversimplified and distilled down into an energy balance equation. Applying the calories in, calories out methodology does not address the complexities of biology involved in this process. Human biology is intimately connected with the environment, and when we look at it through the black and white energy balance lens, we set our clients up for failure, and some potentially serious downstream effects.

There are several clinically relevant targets in weight regulation, and contrary to the current dominant narrative, counting calories doesn’t fall under this umbrella.

Although energy balance, which is where the popular theory of calories in or out comes from, is important in the equation, expanding the lens through which we work with this concept is paramount. It’s important to look to the key regulators of energy balance and modify those, rather than manually manipulating calories based on dated equations.

One of the driving factors of energy balance is stress. Therefore, stress is an integral area to explore when working with clients whose primary goal is weight loss.

Stress and Weight Homeostasis

In acute stress we often see a suppressed appetite. This can result in short term weight loss, but the script is flipped when acute stress shifts into chronic stress.

Stress, which can be real or perceived, causes a disruption in the biological processes that are responsible for homeostasis. A characteristic of homeostasis is the ability for the body to regulate weight. When the biology underpinning homeostasis is disrupted, changes to weight occur.


Let’s take a deep dive into how stress interacts with these biological processes.

The Science of Stress

Stress is highly associated with consistent weight gain, the inability to lose weight and poor weight regulation primarily due to its impact on hormones.

The interplay between leptin, ghrelin, cortisol and insulin affect not only the foods that we choose to consume, but they regulate energy balance through the way in which they interface with the central nervous system and energy substrate metabolism.


Trajectory of Cortisol


Cortisol, the primary stress hormone, is secreted in response to HPA activation. Cortisol stimulates gluconeogenesis, which increases insulin production.

Insulin, we know, is an anabolic hormone, which in addition to blunting beta oxidation of fatty acids, tells the body to store fat.

In the long term, the increase in blood sugar via the cortisol-induced gluconeogenesis decreases insulin sensitivity and promotes insulin resistance - a characteristic of obesity and weight gain. Often, the degree of insulin sensitivity has a direct correlation to the extent to which an individual is able to maintain a healthy weight (note: a healthy weight is different for everyone and can vary during different stages of life).

In the case of chronic stress, cortisol and thus insulin, are consistently elevated. These two on their own have their independent relationships to weight gain AND together they work synergistically to upregulate lipogenesis - the creation of fat.

Chronic stress and metabolic flexibility cannot co-exist. Stress automatically shifts glucose into the driver's seat and it becomes the primary fuel source, allowing adipose cells to accumulate fat and expand.

Lack of Willpower or Stress?

We tend to separate physiology from psychology and oftentimes, our clients are under the impression that they just need more willpower in order to reach their goals. To just say no to their vices. It’s important for them (and us!) to understand that willpower is determined by our current physiology.

Excess cortisol is a survival response and it tells the body to load up on energy dense foods. The research shows a trend towards consuming a western style diet in the face of stress. Ie - there is a higher consumption of sugar and less intake of nutrient dense foods including fruits and vegetables.

When people are living in fight or flight their behavior inherently shifts and often we see food (subconsciously) become a coping strategy rather than a means to supply nourishment for biological needs. Key point: managing emotions overrides biological needs.

We also know that the hormones, molecules and the metabolites associated with stress interact with the brain in a way that negatively impacts executive function and self-regulation. These are two areas that are fundamentally involved in our ability to make beneficial choices moment to moment.

In addition, cortisol is known to alter leptin and ghrelin levels. These two hormones regulate appetite and satiety. When the synthesis, secretion and receptor sites of these two hormones are altered we inherently consume more calories and we see a shift towards calorie-dense and nutrient-depleted foods, which is driven by our biology, not our lack of willpower.

Therefore, in the presence of stress, the concept of willpower is null.

Calorie Deficits in Stressed Out Clients

We can utilize a calorie deficit and still see results in stressed out clients, with the caveat that it is only a short term solution.

The kicker though? Putting a client, who from a physiological standpoint is stressed out, in a calorie deficit sends the body into a state of survival, increases stress (ie- upregulates cortisol) and further disrupts homeostasis. The effects of this can be:

  • Burnout

  • Chronic illness down the line, including cancers

  • Nutrient deficiencies (the stress process uses up a lot of nutrients)

We can swim upstream, but it’s easier and more desirable to go with the current. Restricting calories is asking out clients to fight the current - correcting the drivers behind food consumption allows them to flow down stream.

Wrapping It Up


Knowing the clinical targets of weight loss and which ones apply to your clients and patients simplifies your client’s protocols, and client compliance is magnified. This allows for faster, more effective and long-term results.

The research on stress reduction shows that even simple interventions such as adding in a breath practice or incorporating adaptogens has statistically significant and profound impacts on weight regulation- without intentional calorie counting or deficits.

Helping a client get to their own unique ideal weight can be an empowering experience for both them and you, the practitioner.

A body that is in homeostasis will automatically eat for its biological needs. Therefore, if we regulate physiology, counting calories and monitoring energy expenditure becomes unnecessary.

In our mini course, A Functional Medicine Approach to Weight Loss, we dive into stress and other clinical targets of weight loss and provide solutions + guidelines on how to determine which ones are relevant to clients. Check it out here and elevate your protocols + client results!




Author: Lisa Kowalyk, Co-Founder, Fiore

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