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Posted on Nov 9, 2010 in Weight Loss | 6 comments

Weight Loss Math

So as a seasoned dieter and weight-loss-fake-starter, I can tell you that it isn’t really news that weight loss is a math equation. Let’s be honest, we all know this. Calories in versus calories out. If you expend more calories than you eat, you lose weight. Ta-da! From that perspective, it would seem that it’s this kind of math:

But when you really get down Ā to it, and you are actively trying to lose weight, you don’t want to hear that it’s that simple. You don’t want people to tell you that it’s an easy equation. Because losing weight is hard. It is. It’s a daily struggle, and the successes and failures that you suffer day to day make it actually a lot more like this:

This is me trying to figure out my own personal weight-loss equation, the answer to seemingly endless questions as I continue down this road. How many calories should I really be consuming? How many weeks should I reasonably set for my goal? When I started this journey, I picked 1500 calories fairly arbitrarily. While I’ve obviously flexed in both directions on different days, I thought it was time to sit down and really sink my head into this math, especially since I’m now almost 34 lbs lighter.

Thank goodness for Google, that’s all I have to say. A few deft strikes of the keyboard and I found a BMR calculator that helped me figure out my restarting point. At 22 years old, 5’9″, and 212 pounds, my basal metabolic rate (the rate at which I burn calories simply by being alive) is 1798 calories a day. Add in the Harris Benedict Equation (which helps roughly figure out how many more calories you are burning based on your activity level) I determined the following:

If I am sedentary, with little or no exercise in a given week, I’m burning approximately 2,158 calories a day.

If I am lightly active, exercising 1 – 3 times a week, I’m burning approximately 2,472 calories a day.

If I’m moderately active, exercising 3 – 5 times a week, I’m burning approximately 2,787 calories a day.

I won’t go into the results for very or extra active because who am I kidding? Hahaha. So what do these numbers mean, exactly. Again, this is probably information that most of you are already well aware of, but let’s refresh the Dieter’s Golden Nugget of Knowledge just in case:

1 pound of fat is approximately (I am using that word a lot today!) 3,500 calories. So as logic follows, in order to lose 1 pound a week you need to have a deficit of about 500 calories a day. Now as I obviously want to be losing more than just 1 pound a week, you just multiply up from here and you can figure out what you need to lose 2 pounds a week, and so on, and so forth. What this means for me is that my original goal of 1500 calories a week… is just about right for losing around 2 pounds a week. So how do you like that! Guess my arbitrary number isn’t looking quite so arbitrary (what is with me and reusing words today?) anymore, huh?

If I maintain a lightly to moderately active lifestyle, and stick between 1500 and 1800 calories a day depending on my activity level, that should keep the pounds coming off at a fairly regular rate. In fact, if I continue to lose 2 – 3 pounds a week, I should be able to reach my end goal of 165-ish pounds in 17 – 25 weeks! And my birthday is in 22 weeks, so I figure that’s kind of perfect. šŸ™‚ Now, of course, the math is just half the battle. Enforcing the calorie-counting and exercise regiment is the important part. Obviously this isn’t a perfect science. You hit plateaus. Your body is constantly adjusting its needs based on your lifestyle, and as I continue to lose weight I’ll probably need to whip out theĀ abacusĀ once more. But it is comforting to know that there’s some sense to all this. There’s some rhythm. Something reliable. And as long as I can put in the effort, stay the course, keep on track, I’ll get there in the end. It literally is a journey. And with that poetic ending, I bid you adieu!


  1. Nicely reasoned…nicely phrased!!

  2. Well reasoned! Well phrased!!

  3. I think it’s good you calculated everything for yourself. You’re really learning about nutrition, I didn’t when I did Weight Watchers. I hope you keep losing and get to your goals.

  4. it is a journey….we often forget that the body is ever-changing and it’s hardly prudent to put into equation boxes (as much as we might want to be able to)…i hear the trick is “listening to your body” but i really have never mastered that and i understand how difficult that is….i suppose we have to recognize that our equations change with our bodies and doing the best we can with what we’ve got is all we can ask for…you’re doing a great job, if i haven’t mentioned…xxxx

  5. You may not be interested to hear this but it is best to be eating between your BMR and AMR. If you eat below your BMR, your body may eventually go into starvation mode. And that is not a good thing. I get the wanting to lose the weight as quickly as possible but I would not aim for a 3 pound/week loss but rather 1-2lbs/week on average (that is what WW suggests to be a healthy rate).

  6. I think it is fantastic that you have opted to change your eating/exercise habits to achieve a healthier overall lifestyle. I know it’s hard to, on top of that, have to incorporate weight loss, but you are doing it pretty smart, just have to keep expectations realistic. And once you reach your target weight, you will have set the foundations for healthy living for the rest of your life!


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