Sunday, October 16, 2011

Back to Basics Part One: The Math Behind Your Weight Loss Goals

I hear this question a lot (and I’m pretty certain you do too): What do I have to do to lose weight? It seems like such a simple question with a “magic formula” answer. There is no magic formula to losing weight, but there are ways to make the process much less like some sort of black hole. The basics? Diet and Exercise. Besides plastic surgery and weight loss drugs, there is no other healthy way to lose weight. And no, that was not an endorsement for either plastic surgery or weight loss drugs...

You want to lose weight, but you don’t want to starve, right? And it’s very difficult to start figuring out how much you should eat. However, people have spent years and years gathering information and analyzing data to make the job easier for you. Here’s how it works:
  • You consume food
  • Food consists of fat, protein, and carbohydrates that provide energy
  • This energy is measured in kilocalories (but usually, we just say calories)
  • Your body uses this energy to function (run, walk, digest, talk, exercise, etc.)
  • Whatever energy is left over that your body did not use is stored as fat
I know that was thoroughly simplistic, but hopefully, it demystifies the process. This is why the calorie is a very important measurement because it helps us decipher what our body is storing as fat. I like to call it the “Eat minus Burn”.

How do you calculate how many calories are in your food? Well, you could hire a Food Scientist, or you could use the cheapest tool available: the internet. As we all like to say, Google is your friend. It’s amazing how many websites available tell you how many calories are in your food; even local food! Some websites even go as far as telling you specific details of the meals in fast food restaurants. We do have so much information available to us.

But then that brings us to the question “How do I know how much I should be eating?” Most people calculate their calories per day for two reasons: One, it’s easier to do daily than weekly. Two, if you do make some mistakes one day, you can leave it behind and move on to the next. However, whatever way you choose to calculate, the calories you should be eating depend on a lot of things because every individual is different. We all have different heights, weights, ages, and sexes. Yes, your sex is a determining factor too!

To figure out how many calories you need, you need to first determine what your BMR is. BMR is the body’s Basal Metabolic Rate, that is the amount of energy you exert daily just being alive, eating, sleeping, showering, etc. Here is the formula for BMR (W = Women, and M = Men):

W: 655 + (4.3 x weight in pounds) + (4.7 x height in inches) - (4.7 x age)
M: 66 + (6.3 x weight in pounds) + (12.9 x height in inches) - (6.8 x age)

Yes, men burn more calories just being alive. I know, just one more reason to be upset. Yes, I am jealous in this case. Don't judge me.

Anyway, let’s assume that when you plug in your numbers you get 2000 calories. This means that you can eat 2000 calories a day with no exercise, and maintain your current weight. Our current estimate is:

2000 calories

Now, if you do some form of exercise (even the minimum), this means you can eat even more and maintain your current weight. Again, you can Google all sorts of exercises, and calculate how much you burn based on distance, speed, etc. but we’ll talk more about the basics of exercise next week. Essentially, based on how active you are, you can estimate how many more calories your body needs by adding the following values to your BMR above:
  • Basic walking about: BMR x 20%
  • Minimal exercise a couple of times a week: BMR x 30%
  • Exercise most days a week: BMR x 40%
  • Exercise intensely on a daily basis: BMR x 50%
  • Hard labor or intense athletic training: BMR x 60%
So let’s assume that you do minimal exercise a couple of times a week. Your new number would be 2000 + (2000 x 30%) = 2600. You would need approximately 2600 calories just to maintain your current weight. Note that this is an estimate and it completely depends on the kind of exercises you do, but you get the point. Our current estimate is now:

2600 calories

The next step would be to determine how this number would change if you wanted to lose weight. Now, the body works like this: 3500 calories equals 1 pound. To lose weight, you need to determine how fast you can do it in a healthy way. If 3500 = 1 pound, then you have to have a deficit of 3500 to lose 1 pound. That seems like a lot, right? Let’s go back to our example. If you deducted 500 calories a day from 2600 calories, how much would you get?

2100 calories

500 calories less a day means that you lose 1 pound in 7 days (500 x 7 = 3500). That’s totally doable, right? If you were not in a hurry, you could even spread that out over 2 weeks and make it 250 calories less a day.

But let’s backtrack for a second. Remember that we started on an assumption that your numbers produced 2000 calories? These numbers would change based on what your numbers actually produced. I’ll repeat the formula down here so you can start your own calculation:

Hope this helped! Let me know if you have any questions. All of the calculations above can be also done automatically at this website: Just in case you don’t really care about the formulae but are still interested in the actual numbers.

Cheers Eights & Weights!

Photo credit:


  1. This was really helpful and the post also make it seem simple. Waiting for the next on basic exercises

  2. Eye opening calc.. I could never figure out how the daily target was arrived at...

    I have been using to track calories in food and all that.. pretty nifty too I think..... Thanks for sharing..

  3. Great, great, great!!! This was simple and amazing. Now i understand how things work.

  4. Wow, awesome blog, your blog glance really easy. The whole view of your site is very beautiful the content material is also amazing that you have used in it... Go on Bliss Hosting for the best hosting in all over the world


Related Posts Plugin for WordPress, Blogger...