Wednesday, December 2, 2009

Only 101,500 calories to go!

I just love math. Simple math. Calorie burning math.

I found a great little "game" I can play with myself to help keep me motivated on my weight loss journey. A couple days ago I got to wondering exactly how many calories I had to burn in order to lose the weight I'd like to lose. "Well, self... you'll have to define an actual goal before you can find that out..." Oh. .

So I finally took my body fat percentage info out from my weigh-in yesterday.

As of December 1st I weighed in at 185.5 lbs, with a body fat percentage of 32.1%

Calculator says:
~125 lbs of that is lean body mass (bones, muscle, organs, etc).
~60lbs of that is pure fat (uh-oh).

The American Council on Exercise classifies anything above 31% as Obese for women. 25-30% is deemed "acceptable," 21-24% is classified as "fitness" level, and 14-20% would put you in the "athlete category." A woman needs to have 10-13% of her body weight in fat in order for organs to function (and I do like my organs to function). I remember reading that for a woman to be in hormonal balance she needs to have 18% body fat as a minimum.

As I sat with my calculator I decided that figuring out 20% and 25% were going to be way easier than trying to figure out anything in between. I like nice, round numbers. The equation used on the website where I found the ACE stuff was a little confusing, so I just did some of my own renegade math. That kind where you're counting on fingers and drawing pictures and forgetting to "show your work." That kind where you finally get to the end but it was so complicated that you forget how you got there. My math teachers always got frustrated with me. Oh well. :)

I just took my lean body mass (125) and divided it by 4, and then added 125 back in to figure out how much I'd weight if I had 20% body fat. I can't explain without drawing pictures... but trust me... it pans out. Then I took 125 again and divided it by 3, added 125 back in to figure out how much I'd weight if I were 25% body fat. Here's what I got;

20% Body Fat = 156 lbs (125 lbs lean mass + 31 lbs fat)
24% Body Fat = 166 lbs (125 lbs lean mass + 41 lbs of fat)

Those are the numbers I'd be aiming for, assuming that my lean body mass stays the same. But there's a little *twist!*

The little gizmos we use at the gym to measure body fat aren't the most precise method, and can count some of the really deep abdominal fat as lean body mass. I found this out after asking a trainer why my lean body mass was shrinking along with my overall weight and body fat percentage. To be more precise, I'd either have to talk some scientist into figuring it all out using a pool of water (no thanks) or submit to being calipered by a total stranger (also, no thanks). I choose doing my weird math at every weigh-in to update my goals according to my most current readings.

Anyways... back to where my title came from...

So I currently have two weight loss goals. Let's call them an ideal "weight range." Good then. My last weigh-in was close enough to 186 for me to feel comfortable saying I've got 20-30 more pounds to lose to be within my ideal weight range. In the interest of making smaller goals, I'm going to set little 5lb markers along the way. 5 pounds a month is a good solid goal. Here's a little timeline of my goals;

January 1st, 2010 - 180 lbs
February 1st, 2010 - 175 lbs
March 1st, 2010 - 170 lbs
April 1st, 2010 - 165 lbs
May 1st, 2010 - 160 lbs
June 1st, 2010 - 155 lbs

My son happens to turn 2 years old in June of 2010, and I think that's a great little milestone and motivator to work towards. I want my son to have memories of a "fit Mom" and not a "fat Mom."

Okay... back to the math...

I don't have time for a big physiology lesson on how our bodies burn fat (this blog is already too long), but the short version of the story is this;

Fat is energy
1 lb of body fat = 3500 calories to burn
I only "need" 31 lbs of body fat (20%)
I currently have 60 lbs of body fat
I have 29 lbs of body fat that I do not need.
I will need to burn 101,500 calories of energy to get rid of that fat

Rather than thinking of it as

I've decided instead to have the attitude of...
"Ooooh! Think of all the wonderful things I can DO with those calories!"

Since my goal is to lose 5lbs a month, that means I've got 17,500 calories a month I can use up.

I'll keep you posted on how this fun little math game goes. :)

DISCLAIMER: I apologize if this was confusing. I left out a bunch of details that could have made this a much longer entry. Thank you for reading.


  1. I'm on this journey with you. My daughter turns 4 in March and I want to be at my ideal weight by then. I set myself for at least 15 lbs a month, but I'm practically starving myself too. She's my third child and I never had this trouble losing after I had my boys. Anyway, running and diet is truly helping. Just wanted to let you know you've got a partner in this journey.

  2. You're a math nerd like me - I love it! Way to figure things out, Becca Sue. And 5 pounds a month is a completely reachable goal. I'm so glad I get to read about your adventures on this journey. :)

  3. HAHA! Becca Sue, this was a fantastic blog! I don't know if I follow all your math, but I do in fact trust you because you're a very smart woman. Great perspective on looking at that calorie burn as 101,500 opportunities for fun :)

    Do you ever do workout videos? I'm doing Denise Austin's Fit & Firm Pregnancy. She's absolutely crazy and never shuts up but I really, really love it. Her general approach (sorry if you already know this) is simple fitness - working out about 30 minutes per day, portion awareness, etc. Not a training-for-a-half-marathon mindset, but a good life-in-general mindset. Fun calorie burning.

  4. Don't be afraid of calipers and underwater (hydrostatic) weighing. If keeping an accurate tab on your body fat really matters to you, the scale is not a very accurate way to keep track. Hydrostatic weighing is definitely the most accurate (and least uncomfortable) of your better options. Also, I'm pretty sure the minimum healthy body fat percentage is 10-12% for ladies, but it probably depends on the person to a certain degree.

  5. Hi Becca Sue,

    I love your 5 lbs a month goal! That's exactly how you should be doing it -- nice and slowly. So many people lose too much too fast by going on a "diet" and when their body gets into starvation mode, they wind up overeating and gain back some or all of the weight.

    What has helped me (I'm a runner also) is to increase my protein and fiber intake to keep me full w/o all the extra calories.

    I talk about maintaining a healthy weight on my blog at

    Good luck to you! I will keep reading your posts!