So often we hear people blame their metabolism for many things…their ability to eat anything and stay thin, or why they eat salad but can’t lose weight. But what is this “metabolism” thing, anyway?
There are actually several different “types” of metabolism. I’ll explain the basics, so that you can get a better understanding of the way your body deals with calories and energy.

Resting Metabolic Rate (RMR): Very closely related to “Basal Metabolic Rate,” (but we’ll stick with RMR, as its easier to remember and pronounce), our RMR makes up the largest percentage of our metabolism. (Between 65%-75%!!!!) Your RMR is the amount of calories your body burns at “rest.” (So your energy expenditure when you are sleeping, sitting, basically doing anything that isn’t physical). This part of your metabolism is pretty constant. And a lot of it is genetic; hence why some people can just “eat whatever they want” and stay thin. But before you get upset that your RMR isn’t “naturally” high, there are certain things that affect it, (and there are parts of your metabolism that you do have control over!)
Things that affect RMR:

• Age (our Resting Metabolism goes down as we age.)
• Percentage of Muscle Mass (Muscle burns more calories than fat).
• Sex (Not how much you have, but men tend to burn more calories than women, usually because of their percentage of muscle).
• Height and Size (The taller and larger you are, the more surface area you have. The more surface area you have, the more calories you burn.)

Thermic Effect of Food (TEF): Your body’s TEF is the amount of calories burned by digesting food, processing nutrients and food storage. That’s right, eating burns calories! It makes up 5-10% of your metabolism. But before you make yourself Thanksgiving dinner every day, there’s a balance between eating too much and optimizing your TEF. Nutrient dense food (i.e. food that contains a lot of fiber, vitamins, Omega fatty acids, etc. compared to how many calories it contains), insures your TEF is running high while you’re not storing too many excess calories. Potato chips and candy are not nutrient dense…they have very little nutrients compared to their calories. So if a lot of “good stuff” is packed into everything you eat, your body will use its energy more efficiently. (Most “whole” foods). I also recommend eating smaller meals, as you will have less “extra calories” that will go into storage after you eat. (And you’ll probably have more energy, since your body won’t have to use all its resources to keep digesting.)

Physical Activity energy expenditure (PAEE): Can you guess what this is?? Exercise! Physical Activity usually makes up 15%-35% of your metabolism. Why such a large range of calorie burning? Because there’s such a large range of activity you could be participating in. If you spend your day off watching TV, a lot less of your calorie burning will come from PAEE. If you go jogging, lift weights, and then go dancing, your PAEE will make up a much larger percentage, and usually burn more calories. Physical activity is anything that requires physical effort. Construction workers often get their activity on the job. Europeans often walk and bike for transportation, getting their physical activity that way. But this isn’t just about weight loss, having a high rate of physical activity usually gives you more energy, as your body burns more calories even after you stop. Plus you get lots of the happy hormones, as exercise releases serotonin in your brain! (Bonus).
Of course you can overdo it, since it is using your body’s energy stores. (When hiking the John Muir Trail, I needed a nap after a few mountain peaks.) But most people in America under-do it, so find a way to get active, your body will thank you for it.

Note: I will be writing many more articles on the benefits of exercise, ways to avoid injury, the best work-outs for you, etc.