Wake up, shower, do hair, get breakfast ready, get kids to school, get a workout in, get to work, pick up kids from school, take kid #1 to soccer, take kid #2 to football, coordinate ride home for kid #2, pick up kid #1, get home, get dinner ready, pay bills, get lunches made for tomorrow, answer emails, BED! Give or take a few tasks on this list and you have a typical day for many clients. Throw in a family emergency or some car troubles and BOOM; the stress levels can hit a boiling point. What does this mean for our health? We are often asked how this type of stress can affect one’s body composition. To find out, let’s dive into what stress is, how it affects the body, and how it can affect body composition.
First of all, let’s clarify that not all stress is bad. A stress free life can also be detrimental to health due to the inability to react to various challenges in life. Our reaction to stress is what determines health and the effect stress can have on our bodies. If an individual reacts to stress as a challenge they have control over, a “fight” hormone is released (norepinephrine). If this stressor is increased or perceived as something that takes over control of an individual, then a “flight/anxiety” hormone is released (epinephrine). If a given stressor is prolonged and or creates a feeling of hopelessness, the individual will become more stressed and eventually feel defeated. Our brains have the ability to select the fight, flight, or “defeat” response based on how we perceive these stressors in life. Although these pathways work together, they each uniquely affect the body. For example, the fight/flight response causes an increase in heart rate, and the release of fat into the blood. Prolonged stress and feelings of defeat activate sections of the brain which results in the release of cortisol from the kidneys. The “defeat” response and subsequent release of excess cortisol may lead to increased fat storage, increased abdominal fat around organs, breakdown of muscle tissue, and suppression of immune function.
The primary hormone everyone talks and hears about when stress is mentioned with regards to weight gain is cortisol. You have probably seen the absurd cortisol blocker supplement commercials that supposedly suppress cortisol release (no evidence that they work and even if they did, cortisol levels are not something you want to alter without medical supervision). Cortisol is a hormone in the body that is released due to fasting, food intake, exercise, waking up, and psychosocial stressors. Its primary roles are energy regulation and mobilization. Cortisol selects the type and amount of protein, fat, or carbohydrate needed to meet the demands placed upon the body. Cortisol also has the ability to tap into fat stores and move fat from one location to another or deliver it to working tissue. While normal cortisol levels are vital to life, chronic excess cortisol levels are believed to be detrimental.
Cortisol can be detrimental to body composition because of its role in the breakdown of muscle tissue for conversion into carbohydrate AND the direct effect on fat storage in stressed individuals. The breakdown in muscle has ramifications to metabolic rate, since muscle mass is one of the main contributors to metabolism. The lower your metabolism, the fewer calories you burn. The exact mechanisms for increased levels of absolute fat storage with regard to chronic cortisol levels are unclear. Like most things in the body, there are often a variety of factors that lead to a given outcome. With regards to cortisol and fat storage it is probably a combination of decreased immune function which may increase illness/fatigue which may decrease activity. Add all of this to a decrease in muscle mass and you have the potential for a significant decrease in metabolic rate = caloric surplus (fat gain).
One thing that is clear in regard to fat storage and cortisol is the potential for increased fat in the abdomen and surrounding the organs. Cortisol has the ability to mobilize fat from all regions of the body (including circulating fat from food). Since cortisol is most active in the abdominal region close to organs, more deposits are made in this area. Increased fat stores in the aforementioned areas increases risk for cardiovascular disease, not to mention they don’t look all that great either!
In addition to cortisol’s effect on our bodies at the tissue level, there are also some psychological effects. Studies on both animals and humans have shown cortisol injections are connected to increased appetite, sugar cravings, and weight gain. It is thought that cortisol directly influences food consumption by acting on the region in the brain that controls appetite. There is also evidence that chronic levels of circulating cortisol can also increase or decrease other chemicals that are responsible for appetite control. The effects of chronic cortisol release on appetite make food logging during periods of high stress even more important. Knowing the calories of an item may be enough to overcome a craving or incentivize you to find something that is lower in calories to cure the craving.
The best way to reduce chronically high cortisol levels is to reduce stress. Physiological techniques to do this are well out of my scope and everyone’s stress is too complicated to generalize with a uniform solution. However, one great way to reduce stress is exercise! Numerous studies show that exercise can significantly reduce stress levels. The next time you think you’re too stressed and too busy to workout, think again! It may be the best thing you can do!