Monday, November 5, 2012

Tracking my Weight - Or Not (Percent Body Fat - PBF)

In order to stay on track, I need to track my "weight". 

In order to stay sane, I need rules about this.

Let me explain that: 

- First of all, I mentioned before that I'm not really trying to lose weight, I am trying to get healthy and fit.  My measurements for that will primarily be a combination of Percent Body Fat (PBF) and Blood Pressure, along with Cardio stamina/health, if that can really be measured.

- Second, I can get obsessive.  At one point in my life, I belonged to Weight Watcher's.  Great organization in some ways, but the live weigh-ins were horrible for me.  They want you to weigh in every week.  They congratulate you if you lose even a quarter of a pound, but on the other hand, I had at least two different "official" people comment on weekly weight gains loud enough for the whole room to hear.  I used to stop drinking water on the days I had to weigh in, and eat almost nothing.  That isn't healthy.  And can't be maintained as a healthy lifestyle.  Remember, this is about health, not weight.

- Third, it is a fact that within a day, your body gains and loses weight.  Every time you eat or drink something, you gain weight.  Every time you use the facilities, you lose weight.  If you sprain an ankle, the fluid retention of the swelling means you gain weight.  Every time you breath out, you lose a tiny amount of water weight from the water vapor released.  Are we getting ridiculous here?  Yes, to make a point.  A relatively typical person will gain or lose 2-5 pounds cyclically every day.

- Fourth, weight fluctuates from day to day.  Based on anything from the amount of sodium consumed to the effects of the moon phase and sunspot activity, weight is not stable, even if consumption and exertion levels are.

So... I need to be relaxed and sane about this - but how?

Well, I try to track my weight based on two rules:
- First, weigh-in every week but only weigh once a week.
- Second, don't worry about a weekly weight gain - look at this week compared to two weeks ago.

And, I use another App on my Android phone for this.  A simple app called Weight Tracker++.  It allows me to see a graph of my weight loss on my phone or tablet, and if I really want I can export the data to a .csv file that I can import to Excel or Open Office to make a chart on my computer.  It also has a "statistics" page where it tells me how many entries I have, elapsed time since my first entry, Latest, Highest, Lowest, and Change in weight (for example right now it reports that I was 323.8 on 9/13/2012 and 310.0 on 10/31, for a loss of 13.8 pounds over 1 month and 18 days (a total of 8 entries).

And this may be repeating myself, but...  I'm not concerned about my actual goal "weight".  And BMI?  Don't get me started on BMI!  BMI was never intended to be applied on an individual basis.  As a measure of a person, it relates height and weight to each other in a way that allows researchers to generalize about large populations of people.  But it counts the same whether the weight entered into the formula is muscle, fat, or because you haven't gone to the bathroom in a really, really long time.  It doesn't take into account bone density, muscles, or for that matter it doesn't take into account if you just drank a half gallon of water.  Even as a research generalization, it is mediocre, but often the best available since most studies didn't take the time and cost to analyze the percent body fat of the people in the studies.

I've chosen to set my goal on Percent Body Fat (PBF).  PBF is a really good measure for health.  It is probably the best "weight" tracking measurement we have available.  It doesn't matter how tall you are, it isn't concerned with how much of your weight is bone.  A male non-athlete PBF of 14-17% is considered "fit", although adjustments for age and gender apply, and some scales show a "healthy" range which seems to merge the "athlete", "fit", and "average" ranges.  If you want more information, check out

There areinexpensive calipers and bathroom scales that will measure PBF, at least one of which is Wi-Fi enabled and willing to talk to a number of phone Apps.  Unfortunately, I bought a scale that had a different feature I liked (wider platform for better balance), and my scale will only display PBF as part of a combination of Percent Bone, Percent Muscle, Percent Water, and PBF.  Unfortunately for me, if any of the 4 is out of range, my scale won't display any of them.  And since fat doesn't contain water, and the scale won't report if Percent Water is below 45%, and I have a LOT of fat on my body...  The scale will only display my weight until I get down to some magical point where there is enough water in my body to make my scale happy.  SHEESH!!!!!  Oh, and calipers are not recommended for obese people.

So, I don't know what my PBF is at this time, but once I get to a reasonable weight range, I will be looking to get my PBF down to about 16%.

Oh, and it may not seem obvious, but the method that bathroom scales use to calculate PBF is "mostly" accurate, and uses low-level electricity to sense body content.  Hydration levels and dampness of your feet will affect the measurement.  Some of these scales say that people with pacemakers should NOT use them.  Some Gyms and Fitness Centers will do a caliper measurement calculation for you to estimate PBF.  Either of these methods has a +/- accuracy of something like +/- 10%, although some people claim the calipers have a much lower error percentage in trained hands.

Doctors have other methods that are more accurate, everything from tanks where they measure how much water you displace when you get in, to a machine that scans you with two different frequencies of X-Rays, one of which is absorbed more by fat, then compares the two images to estimate the PBF.  I'll skip the X-rays, thanks!  There is also a machine now that uses air displacement to calculate PBF, which claims to be as accurate as the dunking method.  It is certainly faster and more convenient, although I have no idea how much it costs.

Any of the methods of measuring percent body fat should at least show if you are making progress.  My plan is to get down near where I think I should be, measuring weight at least until my scale will measure PBF, then tracking both but concentrating on the PBF.  Once I get where I think I should be, I'll arrange to visit a "Bod-Pod" air displacement or dunk tank water displacement center where I can get a real measurement.  The cost of that is high enough that I don't care to pay it until I think I am where I should be.


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