What Drives Your Metabolism

It's a new year, filled with all kinds of New Year resolutions.  Lots of people put losing weight at the top of their list of things to do this year.  The unfortunate reality is that in January the gym will be crowded and the grocery store will be out of their healthiest foods - and come March the gym empties out and the ice cream section of the store looks bare.  With that in mind, I thought it might be a good time to talk about the dirty details of what your metabolism really is and what makes it tick.

Your metabolism is not a static thing.  This means it is constantly changing.  You cannot think that on Monday if your body requires 1798 calories to maintain itself, that on Tuesday it will need the same.  It changes everyday depending on more circumstances that you can fathom.  Webster's Dictionary defines metabolism as "the chemical processes by which a plant or an animal uses food, water, etc., to grow and heal and to make energy".  So our metabolism is kind of like our engine.  It is the force that keeps our body running.

There are a number of things that determine how fast our engine (metabolism) runs.

• Are you sick?  Illness increases our metabolism because we now have to pump cells quickly around our body and work harder to fight infection and viruses.  A fever is an excellent example of this.  We are increasing our body temperature to kill off a virus or bacteria, and that heat is produced by increasing our metabolic rate.
• Sweating is a result of increased metabolism.  Part of the end-product of energy use is carbon dioxide production (which we expel through our lungs) but another part is heat production.  Think about the definition of a calorie - the amount of heat it takes to raise 1 kilogram of water by one degree Celsius.  The number of calories we burn is calculated using this same formula.  So anything you do to sweat causes your metabolism to run at a faster rate (even if it's just temporarily) and it proves this by raising your body temperature which makes you sweat.  Not feeling like working out?  Try leaving the air conditioning off and induce your own fever!  A little temperature shift outside your comfort zone isn't always a bad thing
• How much of your body is fat and how much is lean muscle mass?  Muscle weighs more than fat, it takes up less space than fat, and it also requires more calories to maintain it.  In non-obese subjects it was estimated that 13 calories/kg were burned per day for muscle mass while only 4.5 calories/kg were burned per day for fat tissue. (1)  So for every pound of muscle you are burning an extra 5.9 calories per day.  While that sounds somewhat sad and pathetic, just remember that if you burned off one pound of fat and built one pound of muscle, it may only change your weight by 0.5-1 pound per year, but the health benefits and your size would show much more benefit than the scale weight.
• Have you eaten?  This metabolic factor is know as the Thermic Effect of Food (TEF) aka Specific Dynamic Action (SDA) of food or Dietary Induced Thermogenesis (DIT).  Don't we love to sound super fancy when we talk about whether or not you have food in your system?  When we eat something, it requires energy for our mouth to chew it up, it to churn in our stomach and then to be further broken down/digested and absorbed by the body.  The result of eating one meal can continue to show an increase in energy use 6 hours later!  Having food in your system can increase your metabolic rate by 10% if we utilize the Harris Benedict equation for estimating daily energy expenditure.  This does not mean you need to constantly be shoveling food in your trap to keep your TEF revved up.  It does mean you have to make it a priority to eat within an hour of waking up in the morning.
• Rev up your mitochondria.  Yes, let's take a step way back as far as high school biology... which is probably the last time most people thought about the mitochondria in your cells.  This is the "power plant" in the cell.  It generates ATP which is the energy all your other cells use.  So it would stand to reason that the more ATP you're producing, the more energy you will have.  How can you get more mitochondria to work their magic?  Create some more with exercise!  Endurance exercise, in particular, was shown to increase the size and number of mitochondria in your skeletal muscle cells (2).  So if you exercise, you create more mitochondria, which keeps your body working more efficiently and producing more energy.  This in-turn makes it easier to burn more and have more energy for tomorrow's workout.
• Are you male or female?  Sorry ladies, but men genetically will have a faster metabolism simply because biology predisposes them to have a higher muscle mass.  Now, take a little look around your local Walmart and you can see that obesity doesn't really care what bathroom you use, but from a medical standpoint, a healthy weight male will typically have more muscle and less fat tissue than a healthy weight female.
• Are you old or young?  Or somewhere in the middle?  As we age, our metabolic rate will naturally trend down.  Doesn't have to be that way.  I actually feel that this is due somewhat to changes in hormones, but more importantly due to a sedentary lifestyles as we age.  So I don't usually consider age a factor, but more so what you've done with your body as you've aged.

So right about now you're probably looking for the magic pill!  The one thing that I can recommend that will completely transform your metabolism so that you can sit around on your chubby butt, watching tv show marathons, eating whatever you want while the fat just melts off you.  Seriously???  Was that your New Year resolution?  To put in no effort at all?

Get up.  Do something.  DO ANYTHING!  Stop watching tv... it's all garbage anyway!  You have to move your body.  You have to change the foods you eat.  You have to change your whole approach to the treatment of your body.  It's not just about squeezing into that smaller pair of jeans, or prepping for the big High School reunion.  Your job right now is to get your engine running so you don't find yourself at retirement age, unable to take a ride on your luxury sport boat without your iron lung and motorized wheelchair.

If you took one trip to the gym this week, you would instantly change the number and size of the mitochondria in your cells just with the walk into the facility.  If you started eating breakfast at 7 instead of waiting until 11 to begin your food for the day imagine the difference such a small change could make!

Want to know how to "rev-up" your metabolism?  How about if we start by changing your perspective a little and stop blaming this mystical equation on your weight loss problem and start looking at the problem with your motivation?  Changing your body for the better is going to take hard work, but I guarantee you won't regret it when you get that ball rolling in the right direction.  You increase your metabolic rate by constantly telling your body that it needs to become better at producing more energy.  So you have to get your body to use more energy so that it will understand that it needs to make more.

(1)  Wang Z, Ying Z, Bosy-WEstphal A, Zhang J, Zhang J, Heller M, et al. Evaluation of Specific Metabolic Rate of Major Organs and Tissues: Comparison Between Men and Women. Am J Hum Biol. 2011;23(3):333-338.
(2)  Holloszy JO. Regulation by exercise of skeletal muscle content of mitochondria and GLUT4. J Physiol Pharmacol. 2008;59(7):5-18.