Underestimating the impact of stress:
When we think of stress, we often think of the negative impact of stress called dis-stress. But stress can be useful to help motivate us, learn new skills, finish a project or improve our fitness; this we call eustress. Stress is defined as an increase in demand on the body for change. There are many different types of stress and a complex system of nerves and hormones are involved in the different stages of stress.
The General Adaptation Syndrome is a description of how your body responds to stress.
A scientist, Hans Seyle, in the 1940s, was first in describing this phenomenon.There are 3 stages, which provides an easy way to understand how the body responds in each stage.
In the alarm stage, the body sends a signal to the hypothalamus in the brain which responds by sending signals down to the adrenal glands. The adrenal glands release cortisol and adrenaline. We call this the flight or fight response. In this stage, the body’s heart rate, respiratory rate and blood pressure increases. The pupils dilate. The body mobilises glucose and breaks down glycogen from liver and muscle to supply energy to the active muscles and brain, to allow the body to engage in more strenuous activity than normal. (Remember, stress can be real or perceived and the body responds in the same way). If the stress is resolved, the body returns to homeostasis via the parasympathetic nervous system. However, if the stress continues, the body moves onto the resistance stage. Here, the heart rate, respiratory rate and blood pressure may return to normal or stay slightly elevated, but the body is still in a hyper-alert state. The body attempts to adapt to this higher level of stress by continuing to release stress hormones, which results in the suppression of the immune system. At this stage there may not be any symptoms or they are mild and dismissed. In the exhaustion stage, the body no longer has the resources to cope with stress and we experience burnout. Symptoms at this stage include fatigue, depression, anxiety, insomnia and reduced tolerance to stress, weight gain or difficulty losing weight.
Measuring stress hormone such as cortisol, adrenaline or noradrenaline is tricky. Cortisol has a diurnal variation (varies from highest in the day to lowest at night) and the other two are short lived. It is possible to measure cortisol and its relationship with DHEA, but you need to have someone experienced in interpreting blood markers in context with your history and symptoms. You could also measure cortisol in saliva or urine. There is a price tag to these tests and may be useful in some situations but as with any test, context matters more. What I mean by this is that the benefit of a test should provide information that either completely changes your management, excludes a hypothesis or used to track progress of an intervention. My clinical professor in my first year of medical school said that your clinical skills should provide you with 90% of the information you need for your diagnosis, differential diagnosis or hypothesis. (what did we do when we didn't have fancy tests?).
What I do is take a lifestyle survey of my patients for what I call resiliency buckets. When we experience constant stress, we draw on extra resources in terms of energy (physical, mental, cognitive, emotional). When the amount of stress exceeds our ability to recover, we experience a depletion or burnout. Managing where we are receiving restorative energy and building resiliency allows us to continue to perform under stress and avoid exhaustion. And even when we are exhausted, this is helpful in identifying what is a priority for recovery to restore balance.
There are 4 of these areas and I have attached a version of this here as tool for you to do on your own. These important areas are sleep, physical activity, nutrition and social support or relationships.
Questionnaire credit: The Human Factor Ltd
What the scores mean:
0-3 You have excellent resiliency
4-6 You have reasonable resiliency
7-10 You would benefit greatly from improving your resiliency
11-16 It's time to take this seriously, and take specific action to improve your resiliency
If you scored high, working out a solution for the area(s) you score the highest is a step towards filling up the buckets and restoring resiliency. Different people also respond differently to stress and just because you don't feel stress it doesn't mean that the body is not responding, as you can see in the resistance stage.
Many conditions such as chronic low grade inflammation, metabolic disturbance and nutrient insufficiencies do not have obvious signs or symptoms and may benefit from more targeted testing to identify the underlying drivers (stay tuned for another blog on finding a qualified provider to help you assess).
Another area where I see stress present acutely and over time is when I encounter patients in my cosmetic or aesthetic practice. I observe a lot of variation in a person's skin that is closely connected to their health and the effect that a suboptimal level of resiliency. You can see the impact of daily stress and lifestyle factors and how you will age over time through an interesting software that takes a picture of you, assesses various aspects of your lifestyle and predicts how your skin will age in the next 10 or 20 years. While it appears confronting, age-progression software has been used in research and successfully used as a motivational tool for improving lifestyle behaviours. Below you can see an age-progression of 20 years in someone who is experiencing daily stress and bad sleep. You will notice dark circles under the eyes and eye-bags. There are wrinkles around the eyes, between the brows and forehead. The overall skin also appears dull and grey.
Image credit to: ChangeMyFace via www.changemyface.com
Mistaking daily weight fluctuations as fat gain:
Weight on a scale reflects in general 4 basic components, fat, fluid, muscle and bone. I've excluded the weight of organs such as the heart, liver, lungs, kidneys, spleen etc to keep things simple. With healthy individuals, I prefer to use the term body composition rather than weight because this reveals a lot more about a persons state of optimal health and longevity by differentiating fat mass and lean mass (muscle and bone). These are important because low lean body mass is associated with higher risk of death and chronic disease. In addition, the location of the fat (central or visceral fat) rather than subcutaneous fat also increases risk due to the inflammatory nature of this type of fat. Rather than just using a scale, you can also get an estimate of this information from Bio-Impedence Analysis (BIA) scales. They are very accessible measurement these days in clinics, gyms, shopping centres and pharmacies. Unless you know what your body weight consists of, and track this consistently, you cannot differentiate what has contributed to weight change. Let's go through an example of what the numbers mean in a BIA scale, the basic physiology that affects these numbers and how they apply to women at different stages of their cycle.
The example below is from a real free-living female aged 47 who has been doing resistance training for 10 years.
Before starting you need to set your profile based on your age, gender and physical activity. (just for transparency, I get no funding from Tanita, it was easy to purchase online and I chose this version because I personally care about segmental ratios)
Starting from the top left you see the body weight in kilograms (note that 1kg=2.2lbs for those working in conventional units). Next is a number called the BMI (body mass index) which is a ratio between your height and body weight. This is used in research to identify populations at risk of various diseases based on whether they are overweight or obese. There are normal ranges for different ethnicities. In Asia, the normal range is a number between 18.5-22.9. Overweight is 23-24.9 and obese is 25 or above. These ranges are slightly higher for Caucasian populations. This result shows a number 24.2, which is in the overweight range for Asians. You will see how this number can be misleading as I go through the rest the the measurements.
Third in line the number 25.4% is the percent body fat. Underneath the number are normative bars, where green is normal, blue is under-fat and orange is over-fat. This example shows the results to be within the normal range. So how do we reconcile this with the high BMI indicating overweight but have a body fat in normal range?
Keep reading on to find out.
Bottom left is the percent body water at 52% which is in the normal range for women. (the scales come with a normative date so you can also refer to these based on gender). Muscle mass is 45.4kg and you will see that most of the bars are in the orange range (except for truncal muscle) which indicates this person has more than the average amount of muscle mass for their age and gender. This explains why there is a caveat to using only BMI or weight to assess the body composition health of an individual.
Finally, 3.1 kg indicates bone mass, which according to Tanita's reference should be 2.4 or above. (although for clinical diagnosis of bone density, a DEXA is the gold standard).
BIA is not a perfect measure but is a useful tool to assessing trends and composition over time as long as the measurement is taken at a consistent time of day and food or water intake as these fluctuate within a day.
Let's take some time to understand the physiology of the 4 components measured. First bone mass and density formation and resorption is an active process and in a healthy person requires months to complete these stages. The entire adult skeleton takes about 10 years to be replaced and as we age this process declines over years and not days.
Fat mass is also metabolically active and some BIA scales will reflect visceral (more dangerous and inflammatory) around the organs such as the liver (fatty liver) and heart increase risk. Total fat mass requires an energy surplus. An estimate surplus of 3500 calories is required to gain 0.45kg (1lb) of fat. This is equivalent to eating 10 Macdonald’s Sausage McMuffins in day. Many people who care about losing weight are on a calorie deficit rather than a surplus and are unlikely to be eating this way. Everything else being equal, it is unlikely to be the cause of an overnight weight gain. So what’s left to account for this shift? There’s muscle and water left. And just to show you how long it takes for muscle mass to increase, I like to use an example from a Whole Body DEXA. DEXA stands for dual-energy x-ray absorptiometry. This is a type of x-ray that can differentiate between lean muscle, bone and fat tissue. Here is an example of a female and her bone and muscle changes over a 12 month period shown on DEXA. The entire report also has images and segmental ratios like the BIA, but below is the a table of the key differences over time from baseline.
The column to focus on is the LEAN+BMC (g). The number is a combination of skeletal muscle and bone mineral content (BMC) in grams. Over a period of a year the total weight increased by 2463g or 2.5kg rounded up. We have mentioned that bone takes months to build and decreases with age and there was a loss of BMC from 2282g to 2260g (not in this table but in the report elsewhere). So the actual lean muscle mass change is:
(45976 - 2260) - (43513-2282) = 43716-41231 = 2485g (a 2.5kg in 12 months and while impressive for a female is clearly not something that changes overnight). I will also add a note that nutrition and programmed training for muscle hypertrophy was involved during this period of time for this increase in muscle mass to occur.
Now that we have established that bone, fat and muscle mass are unlikely to contribute to daily weight fluctuations, the final possibility to consider is body fluid. Body fluid includes what is in plasma (blood) and what are in tissues (inside and outside cells). This is regulated by many hormones and electrolytes in our body and is vital for survival. You can read more about this here. It is also affected by fluid and food intake, sweating, environmental factors and in women, the menstrual cycle, contributing to daily and diurnal weight fluctuations. Fluid retention, especially in the high hormone phase can lead to a weight fluctuation of anywhere between 1-2kgs. Another important point to note is that when we refuel our muscles after exercise with carbohydrates, our bodies convert this into glycogen in muscles, this also results in fluid shifts into the muscle tissue (which has a beneficial effect). In the body building community, this uptake of fluid into muscle from glycogen repletion helps to give the muscles a fuller appearance. Other reasons such as travel, stress from dieting and increase in strenuous exercise without adequate energy intake as described in Part 1 of this series, are also reasons for fluid shifts. Rather than focus on just your body weight and assuming an overnight fluctuation is due to fat gain, be aware of where you are in your menstrual cycle, be consistent with your tracking and understand the different components that contribute to the weight and the speed it takes for each to shift over time. In some situations it may be helpful for women to measure their body weight in the first half of their cycle or follicular phase where the sex hormones are at baseline and less likely to be confused with fluid retention and to have consistency in tracking over time.
I hope this helps you understand the different terms used to describe the components of body weight and how this is impacted by many factors so that you do not assume that it is simply due to gaining fat.
Please feel free to ask questions, comment, share and subscribe if you have found this to be helpful and want to continue to receive evidence-based and science-based information about health and longevity.
We are all unique and if you have already tried or understand some of these solutions, yet are still struggling you may want to consider a personalised and precise approach. Please contact us for more information about this.
References:
Harvard Business Review
Grogan S, Flett K, Clark-Carter D, Conner M, Davey R, Richardson D, Rajaratnam G. A randomized controlled trial of an appearance-related smoking intervention. Health Psychol. 2011 Nov;30(6):805-9. doi: 10.1037/a0024745. Epub 2011 Jul 18. PMID: 21767016.
https://www.changemyface.com/
https://www.tanita.com/en/understanding-your-measurements/
https://www.chp.gov.hk/en/resources/e_health_topics/pdfwav_11012.html
Nose Y, Fujita K, Wada T, Nishimura K, Hakoda M. Effects of Menstrual Cycle Phase on Fluid Regulation during Walking Exercise. J Sports Sci Med. 2020 Aug 13;19(3):556-563. PMID: 32874109; PMCID: PMC7429427.
White CP, Hitchcock CL, Vigna YM, Prior JC. Fluid Retention over the Menstrual Cycle: 1-Year Data from the Prospective Ovulation Cohort. Obstet Gynecol Int. 2011;2011:138451. doi: 10.1155/2011/138451. Epub 2011 Aug 8. PMID: 21845193; PMCID: PMC3154522.
Comments