How can a very overweight person (such as myself) calculate Lean Body Mass accurately?

I am trying to get a baseline to track my progress (as suggested by Body Sculpting Bible for Women). I have an Accu-Measure body caliper, but it says that for someone really overweight it will not be accurate.

I tried the formula in the Body Sculpting book (Dr. Frederick Hatfield's formula) as they suggested to get a starting point. But after calculating and double-checking my calculations, it says my LBM is 236. This cannot be anywhere near accurate, because if I lost all my fat I doubt I'd weigh 236! The only thing I can think of is it didn't take into account a measurement from my thigh, for example... and I have thunder legs, so...

Does anyone have a formula of some sort that I could use to get a more accurate starting point number? If not, I suppose I could use the 236 and just make sure that number doesn't decrease while I'm trying to lose weight.. would that be an accurate way to be sure I'm not losing muscle even though I think the number is off?

I'd prefer not to go to a gym just to get an accurate number.

Thanks people And to those of you who were helping me in the body type thread - I started today! (I think I should count carrying the weights in from the car, though.. they were pretty heavy )

Again, I think you are over thinking this. Even at a gym, you couldn't get an accurate reading with caliper pinches. If you really want to track it, the only way may be with an expensive, high end scale that does body mass. They aren't really accurate, but the trend is.

You may well have a very high LBM. Remember, that includes bone, organs and skin as well as muscle. When you lose weight, you will lose LBM no matter what. The trick is to minimize it.

Mel

Hi Bingo,

I'm assuming that you really want to determine a realistic goal weight for yourself based upon the amount of lean body mass (bones, tissue, organs, muscle) that you currently have. To do this you will need to get an estimate of your current body fat percentage.

As Mel pointed out most techniques are only estimates in nature and as a rule we really look at the overall trend of lowering. I have found this little device helpful.

http://www.amazon.com/Omron-HBF-306-.../dp/B00006WNPU

Okay. Back to determining your goal weight. I'll just through in an example here for illustration:

Julie weighs 131 lbs and is at 22%bodyfat according to her morning weight in. She would like to reduce her bodyfat percentage to 18%

131*22=28.82 lbs of bodyfat
131-28.82=102.18 of lean body mass
102.18/(1-.18)=102.18/.82=124.61

Her theoretical goal weight at 18% bodyfat would be about 124 to 125 pounds.

Again. Don't get to hung up on numbers. Look at downward trends. I think it is helpful to get an idea of your current bodyfat % and lean body mass in a ball park perspective to kind of know if your goals are realistic.

In my case I thought at 5'3 my goal should be 110 to 115lbs when I began.What I didn't know in the beginning is how much muscle I would be able to retain and build along the way. After finding my current LBM and knowing my goal of 18 to 19% bodyfat, that low of a weight would only be possible if I intentionally lost muscle mass. Since muscle mass enhances our metabolic processes, this would be counterproductive in the long run and increase my chances of gaining weight back due to a weakened or inhibited metabolism.

Good questions. Again. Look at trends. Keep trying on pants that are just a little snug, do a waist to hip ratio. There are all kinds of ways to measure our progress.

Yes! I was trying to figure out where I was.. so I could figure out where I wanted to be. Also, though, I wanted to be able to monitor the trend to see if what I am doing is working or not working. Since I will likely be building some muscle (hopefully!) I don't want to just count on the scale (could get depressing) and I wanted something a little more accurate than just the way my clothes fit, you know? Your examples are very helpful! Also, that handy gadget you linked to looks like it will do the trick - even if it isn't totally accurate for me I can at least see the trend without having to cross my eyes doing a bunch of calculations.

Mel - Yes, I am over analyzing it! I don't know why, but I have always been that way. I want to be fully armed going in to whatever it is and not miss anything that could be important (no matter what the topic). It does make me a little crazy sometimes. Let me know if I ever make *you* crazy, and I will stop immediately.

Maybe.

Hi Bingo,

I would second the Omron gadget Lydia looked up for you. I don't have any personal experience with it, but Omron is a good brand and at that price, you cannot go wrong. (Myself, I dished out $70 for an Omron blood pressure monitor at Costco).
I understand that you don't want to join the gym so the Omron seems to be a really small price to pay and you don't have to worry about calculations.
Myself, I get my BF% measured at the gym - they have a scale hooked up to a computer and it's one of those impedance-based toys. I really don't care how accurate it is, it is just to see (if you persistently measure with the same device) that you are going down and by how much.

I assume that even though those gadgets are not 100% accurate, they do a fairly good job. According to the gym scale, my BF% is 22.4%. Then, recently, I was also "analyzed" by my naturopath who uses BioMarker 2000 (the the name of the device). Hers is not a scale but she put electrodes on my body (so again, an impedance-based type). According to her, my BF was 21.3%. I was almost ready to pop some champagne then I wisely thought it would be better to compare it to the gym reading and I managed to get it the same day. Nope, I am still 22.4% at the gym.
Anyway, the above is just to illustrate that even though not 100% accurate these things do a fairly good job (for our purposes anyway).

My goal is to squish it below 20% (even if by 0.1% - 19.9% would be fine with me LOL) - as you can see, I have a far way to go before I can stand next to Lydia and Mel. :-)