Welcome to part 2 of 3 for our Metabolism & Diet, with a Pinch of Exercise series. Last week you figured out what your basal (resting) metabolic rate was. If you missed the first article, please read it here.
ADL’s Are Your Friend

Our next step is to get an approximate idea of how many calories you burn doing activities of daily living (ADL’s). There are two ways to accomplish this step. We could either break up every day into specific activities, determine the amount of calories expended per activity, and add up all your ADL’s to have a fairly accurate account of calories burnt throughout the day. Or, we could save you a few hours of work; and categorize you based on your perceived level of activity. Think about how active you are on an average day. Consider everything from how you get to work, the type of work you do, how often you go out with friends, how much TV/computer you do, etc. Don’t forget about our first article, be sure to leave out scheduled exercise. We are only looking at activities of daily living! Now you will decide which of the following categories you fall into:

Sedentary    (0.2)
Light    (0.375)
Moderate    (0.55)
Hard    (0.725)
Non-Stop    (0.9)

Beside each category is a number. Take your basal metabolic rate (from the formula in the first article) and multiply it by the corresponding number beside your category. The result is a predicted number of calories burnt from ADL’s in one day. Please note, this is a broad estimation, and by no means meant to be taken as accurate. It is based on an average healthy population. But it at least gives us a starting point. For the remainder of the articles, we will make an assumption that the #’s for metabolism and ADL’s are accurate (just to make life easier).

Take the two numbers you’ve calculated thus far (basal metabolic rate and total ADL’s), and add them together. You will most likely have a number between 1,600 and 2,800. This is the number of calories you burn off on an average day, before doing any scheduled exercise. In other words; if you did not do any scheduled exercise, you will still burn that many calories every day. To illustrate this, I will walk through my numbers:

Age: 28          Ht: 188 cms           Wgt: 79.5 Kgs
BMR = 66 + (13.7 x 79.5) + (5 x 188) – (6.8 x 28)  =  1,905 calories/day
ADL’s =  1,905 x 0.55 (moderate lifestyle) =  1,048 calories/day

BMR + ADL’s = 1,905 + 1,048 =  2,953 calories/day
Pinch of Exercise

Remember the pie chart from article #1? We’ve already filled the two larger pieces with BMR and ADL’s. The last piece of the pie is our scheduled exercise. Let’s say I go to the gym four times every week. I run on the treadmill for 40 minutes at a speed of 6.0 mph and a slight incline of 2.0. Based on my weight and age, I would be burning 14.8 calories/minute . This results in 450 calories every time I go to the gym. Averaged over a seven day week; I’m looking at 338 calories every day. Compare that to my 2,953 calories from BMR & ADL’s. Now we can see why for most people, exercise is the smallest piece of the pie!

If I add both numbers together, I end up with a total of 3,291 calories expended daily!

Now that we’ve taken care of the energy out; we’ll have to make sure we’re managing the energy in. In our next article, we’ll focus on our diets to make sure we’re on the right path to achieve our weight loss/gain goals.

Your Homework: Just to show you the importance of staying active throughout the day; try placing yourself in a different ADL category (sedentary, light, moderate, etc). See how much your calories expended per day drops if you go down a category; and how many more calories you’d burn if you increased your ADL’s to the next category. Pretty interesting stuff…. 

– Stuart