Monday, November 11, 2013

Overweight: The Stress Connection Unraveled

In the course of the last year, we've learned and shared a lot with you.  We've uncovered the basics of less than meets the eye.
metabolism and energy consumption.  We've looked at scams and myths and into the tendency of people to overstate the virtue of a food, nutrient, or ingredient simply to sell their product.  We even looked into the relationship between genetics and obesity.  Often, once we peeled back the layers, we found there was a whole lot

But today's topic is not one of those.  Stress is a big deal and is a very real player in the health of an individual.  And that makes it worth talking about. 

It's become conventional wisdom that cortisol is "bad".  (Ugh - I really hate these kinds of binary labels).  But how does cortisol work on the body?  Understanding this mechanism is the first step in grasping the impact of stress.

Cortisol is produced in the adrenal gland in response to stimulation messages from the hypothalamus. The adrenal gland's better-known function is to produce the hormone adrenaline which kicks off that critical-to-survival "fight or flight" response.  This is the ultimate stress response.  Think of cortisol as adrenaline's annoying little brother.  Not quite as cool, not quite as strong, but always around.  In fact, cortisol follows a natural circadian rhythym - naturally highest in the morning and gradually decreasing throughout the day, hitting a low point at bedtime.  This has some interesting implications for night-shift workers, but that's probably another post.

Just like adrenaline creates an all-out response of the body's key survival functions, cortisol signals the body to go into a form of "preservation mode".  Essentially it's a metabolic depressant.  The release of cortisol reduces your body's conumption of blood glucose, desensitizing insulin receptors, and signals the release of enzymes to release potential energy from alternate sources, like muscle tissue.  It signals your body, saying "we don't know what's happening here, or how long it's going to go on, but we're ready for the long haul."  If you've read some of our other posts about metabolic syndrome, improving your metabolism, or even carbohydrates in general, you start to see where cortisol levels can wreak havoc on a person's weight loss goals.  

And, like adrenaline, cortisol levels are spiked in response to external stimulus.  But instead of a survival threat, cortisol release is triggered by a broad and murky mix of stimuli we lump together under the title "stress".  And, like just about everything else in the human body, stress can be a positive motivator or a chronic debilitator.  So, how do you tell the difference?

Unravelling Stress
Stress is one of those wonderful words that everyone understands, but just about everyone defines differently.  This points to the fact that people perceive specific stressors quite differently.  And, if stress is in the eye of the beholder, how can we possibly hope to classify "good" stress as opposed to "bad" stress?  Science, it turns out, has been working hard on this very question.

According to a meta-analysis of 208 different studies on cortisol responses in humans and animals, there are two key factors that determine whether a situation is stressful or not: uncontrollability and social/evaluative threat.  Let's look at each separately. 

Clearly  nobody is in control here.
Uncontrollability:  This aspect of stress describes whether or not a behavioral change will have any impact on the outcome of an event.  In animal trials, mice who had control over a negative sound response (the buzzer rings when I decide to take the food) had much lower stress responses than those who had no control (the buzzer rings whether I take the food or not).  These same results were reflected in numerous human trials; if the subject perceived they could do something to change the outcome, their stress responses were much lower than those who didn't.

Social/evaluative threat:  As we said before, adrenaline is a survival response.  But a person's social survival (i.e. preservation of one's perception/status in a group) is no less important.  In the studies, tasks that presented a significant "threat" of being regarded or evaluated negatively by others, particularly in an aspect where the person held particular importance or the stakes were personal well-being, the stress response spiked significantly.  Interestingly, in studies of social primates, the submissive members of the clan consistently showed higher levels of cortisol than the dominant leaders.

What's more, stressors that exhibited both uncontrollability and a social/evaluative threat compounded the stress response and the stress response lasted longer than either stressor alone.  Now, I don't know about you, but I can't imagine anything that fits the bill better than a person who has tried and struggled with their weight each and every time they walk out their front door.

Some things that turn out to not significantly predict stressfulness in terms of cortisol response:

  • Duration of stressor.  People were either "stressed" or "not stressed" and for how long didn't relate to the level of stress response.
  • Type of task.  This is a tricky one.  Some tasks are inherently uncontrollable or present a social/evaluative threat (public speaking, for instance), so it can appear that a task, in and of itself, might produce a more significant response.  But when the studies controlled for these elements, the type of task was not predictive.  I'm one of those weird people who actually enjoys public speaking.  But hook up a camera or have my boss unexpectedly show up, and it's a whole different ball game.

The Stress Response
So, given the idea that uncontrollability and social/evaluative threats are the key elements of  negative stressors that elicit the strongest stress response, how do you tell when you're experiencing (or likely to experience) a negative stressor?  This is where I depart from the science and travel out on the limb of my own experience.  Thinking back on these kinds of events in my own life, the signs were clear: worry, over-thinking, heightened response (loud, over-expressive, quick to conclusions), and then there's the physical part.  My hands sweat.  Another thing that I seem to do is anticipate conflict and then start planning to argue.  Basically I start having emotional reactions to logical problems.  

Physiologically, if cortisol spiking signals the body to slow the processing of nutrients and be ready to borrow essential energy from muscle tissue, then "stress eating" (guilty, by the way) is about the worst thing you could do for your body.  This is a prime condition for fat storage.  Studies show that the effects of cortisol last less than an hour, so if you can hold off your urges for that long, your metabolic balance will be back to normal.

The point is, learn to recognize your own stress responses and realize where they are coming from.  Do you feel out of control?  Is your social (including professional) status threatened?  What are the warning signs and are there ways you can re-position the situation to put yourself back in your "happy place"?

Tackling Stress in Your Life
So far, we've established that elevated cortisol levels will suppress your natural metabolism.  Chronically elevated stress is definitely not healthy for your body and will ultimately derail weight loss goals.  Uncontrolled situations and the threat to a person's social status are the kinds of stressors that produce a strong cortisol response.  

I have long been a proponent of a simple life and believe in the principle that "less is more".  But it was only in the last couple of years that I took a determined look at my own life and did a "cost/benefit analysis" of each and every one of my commitments and obligations.  For me, the simple act of actively deciding what to keep and what to let go in my daily life was a tremendous relief.  We wrap ourselves up in so many things that many of us lose all perspective on what it is we actually "have" to do. 

There's really no way around it: if it doesn't involve feeding, sheltering, or clothing yourself or your family, you don't necessarily have to do it.

Once you've gone through the exercise of deliberately evaluating all the stuff you have in your life, you're on your way to seriously reducing the impact of uncontrollability.  Even if there are things that you choose to keep doing which are unpleasant, it's your choice and you're reminded of the reasons for your choice.  That puts you back in the driver's seat.  

I can hear you now through the interwebz, "Michael, that's all fine and good, but it's just not realistic.  There's no way you can eliminate all stressors."  And, gentle reader, you'd be right.  Some things are just plain unavoidable.  But, when those stressors come, I do believe there are a couple of important things you can do to deal with them.

Redefine "control".  This is serenity prayer stuff, right?  What factors can you control in a stressful situation?  If you can't control it, will that factor cause you physical or material harm?  Can you decide that factor is irrelevant to you in the bigger picture?  And, of course, "the wisdom to know the difference."

Be mindful about who's opinion/evaluation you value.  Often, we give others a great deal of power over our self-esteem without even knowing it.  Take that power back.  The circle of people whose assessments of me affect my self-worth is alarmingly small.  And, even then, the context is pretty specific.

"Let the air out."  What are the real stakes in your stressful situation?  Are you going to lose your livelihood?  Will you be harmed?  Will you be impeded in goals that are truly important to you?  Or is it simply unpleasant?  

Finally, when it comes to weight loss in particular, get informed.  The more you know about nutrition, the science behind different kinds of training, the more tools you have at your disposal to achieve your goals.  You'll be in control of your body again - to make it whatever you want it to be.  And realize that things take time.  We didn't get in the shape we are in overnight and our bodies are going to take time to remake.  You are in control - but you have to obey the laws of physics and the basics of human biology.