Anyone monitor their BF%?

So I ordered a body fat percent monitor off amazon (like 30 bucks so figured it couldn't hurt) and I know these things are never 100 percent accurate and everything, but I was just wondering if anyone else out there monitors their BF% on a regular basis and has it helped you at all?

I was pleasantly surprised by the results, only 29% for me (Im 6'6 and down to 312 from 334), which I know is not a good BF% but because of my body image I just imagined it would be much higher. I would say my weight is pretty evenly distributed so I feel it is fairly accurate (it is a hand held one so I have read that if your weight is distributed more in your legs it will be less accurate since the electric pulse flows from one arm through your torso to your other arm), though like I said I know it wont tell me absolutely what it is. Anyways i got it more for a relative scale, i.e. how much it goes down (or hopefully not, but up), and to track changes rather then an absolute measure of my BF. I plan on only using it once a week or so just to track to see how much actual fat and how much lean mass im losing overall.

Also, am I correct in the assumption that the body fat percent is simply the percentage of fat in your body, so if you multiply the BF% by your weight that is the weight of fat on your body, and then if you subtract that weight from your overall weight that is the weight of lean mass in your body correct? Or is water weight part of that equation as well, i.e. overall weight = fat weight + lean mass weight + water weight? Another reason I wanted to start monitoring is to make sure Im not loosing to much lean mass, though to much is relative, I figure I will know what to much is when I see it.

Anyways I was just curious if anyone else does this and if it has helped them in their journey or helped them fine tune their programs or diets or anything like that. Or did I just waste 30 bucks? Any and all thoughts/ideas welcomed!

Thanks!

If have a BF% function on my scale.  I know it's not all that accurate, but it can give you a decent relative figure if you measure it consistently under the right conditions.  It seems to have a variation of 2% in either direction at any given time, but it measured in the high 20's when I started down to 16.5% today.  I don't formally track mine, but I do check on it every week or so just to get an idea.

Maybe somebody can chime in on the overall weight, but I believe it's fat + lean muscle mass + water + bones + organs.  AFAIK, overall weight * BF% should equal the weight of your fat only.

I check mine weekly on the scale at the gym.  I'm doing it to monitor if I'm losing any lean tissue.  They are pretty inaccurate, the measure can jump around depending on hydration and other things, so I recommend that you record it often and throw out the weird readings. 

You can figure out the amount of lean tissue fat you have.  At 312 and 29% fat, you have

312 x .29 = 90.5 lbs of fat

312 - 90.5 = 221.5 lbs lean tissue. 

I'm not an expert, but 221.5 lbs of lean tissue sounds like a lot.  Are you a man? 

At any rate, if it is accurate, then the 221.5 lbs of lean tissue should not change much (or at all) as you lose weight. 

Hehe yea Im a guy.  I have big bones and am big framed so it does seem like a lot, but there is a lot of bone/organs/muscle that have to go around for me since im 6'6''. 

That is the way I was figuring it out (I made spread sheet) so that I was finding the weight of fat,  then just subtracting the weight of my fat from overall weight and calling that my lean mass (muscle, bone, organs).  I wasn't sure how water affected it though, but I feel that will give a good measure of how I am doing anyways.  And I kind of expected the lean mass to go down, though not to much, as I have about 60 more lbs to loose, but wanted to make sure it wasn't going down to much and if it was I was going to incorporate more weights in my plan.  

It is interesting to note though that if I reach my goal weight of 250lbs, and keep my lean mass about the same (220lbs), that will put me at a BF% of 12% (250 - 220 = 30 lbs fat, 30/250 = 12%).  Which I believe is healthy for a guy.  However that would put me still at an unhealthy BMI (28.9).  Anyways just an interesting realization I had, and that all these tools need to be taken in stride and used as a guideline and not an absolute measure of health.  (Im not saying these tools aren't wonderful, for I would never be able to make this far with out them and all the great advice here on CC, but just so they are a guideline and not absolute truth).   

Anyone else have good or bad to say about BF% monitors or how they can be used as yet another tool in this wonderful journey of ours?

I'd say that if your BF% is in a healthy range, then your BMI doesn't apply.

Yep, BMI is out the window for people with a LOT of lean mass. I'm 5'10 with 185lb lean mass and 28% bf. No way I am going to lose 40lb of muscle to get an ideal bmi. Kiss my patoot.

don't worry about your bf%.  They are never right with normal body fat monitors.  The real thing you want to watch is gain/loss of body fat over long-term.  Short-term, your body fat may fluctuate based on stuff like sodium and water intake, so just keep a chart...

My BMI is really high too, but by body fat monitor (Omron, hand-held) puts me at 16.2%, which isn't bad.  My step-on scale had me at 19% plus or minus, and fluctuated more... so they're all a little different.

also, 221 lbs. of lean mass is probably not right.  You would have to have NFL linebacker strength...  I used to think that I could not get below 200 because I did the same math and it came out having 190 lbs of lean mass, which meant that below 200 would be unsafe.  I'm now 196 and 16.2% still, so don't take anything out of those calculations.

My scales show mine, i love knowing all the little details. I have 24,8% BF which is basically a 1/4 of my 137lbs. that mean i have 34lbs of fat therefore 1% of my fat equalls 1.36lbs (at the moment) so if i lose 8lbs i can bring my BF down 6% - yay.

Isnt that far more exciting that just seeing the weight drop and possibly losing muscle

The one I got is an Omron handheld one as well. And yea I didn't think it would necessarily be very accurate, but I was going to start checking it once a week (every Thursday or Friday evening) and putting it in excel to at least make sure its going down and make sure the majority of weight I am loosing is fat and not muscle. But yea I plan on checking it at most once a week, and will never do it more than that, I feel getting a trend will be infinitely better then watching it every day.

Remember that the lean mass figure includes water weight, which is why you can expect a slow downward creep of your total lean mass as you lose the weight - even when retaining muscle mass.

 Though adipose tissue doesn't contain a great deal of water, so you should see a consistently lower bf% over time if you're doing it right.

 221 of lean mass is probably about right, given that it includes water in addition to muscle and bones. Plus, you should have ginormous leg muscles from carrying around 334lbs for a long time - if you keep those while losing weight you should have a killer set of wheels to show off.

okay, true, but I guess what I meant by discounting the 221 number is that it shouldn't factor into goals and it shouldn't produce the notion that it is a minimum number.  It may be correct, but that doesn't mean that the "lean mass" number is useful by itself... it is much more useful as part of a percentage.

Obigmcveyo,  it looks like you have the right idea.  Believe me, when the number starts dropping you'll be thrilled because you'll have both your weight and body fat lowering, and two numbers is better than one!