FFM Dilemma!!

[Vixi]

HELP!!! Did I just get FATTER!?

Please help me out with some advice or an different point of view on this question.

Me = 5'4" 34 years old
I had my body composition analysis done on 9/21/02 and the results were
With a hydration level of 47.31%
FFM = 115.2 lbs
Fat % = 35.4 %

I had it checked again today on 10/26/02 and the results were
With a hydration level of 47%
FFM = 110 lbs
Fat % = 35.5 %
8 lbs total lost since previous weigh-in


This was done sponsored by my local hospital using an electrical impedance scale. Not a home use one, but one of those high end $2,500 ones. I know that a lot of people argue the accuracy of such scales but with the hydration being almost exactly the same I figured it was probably pretty close.

I do weights 3x a week for about 45 minutes each time. I also do 1 aerobics, 1 kickboxing and 1 abs class a week and just started running to prep for a 6k run this spring (Am currently up to 1.25 miles). I need to lose about 35 lbs or so but I sure didn't want any of it to be muscle. My fitness level is pretty good overall. These extra pounds just need to go! My goal has been to get to around 15-18% body fat by this spring but gain a little muscle too. My diet is pretty clean and I am getting around 1,200-1,400 calories daily with about 100g-120g of protein (probably not enough?).

Sorry if I am naive or ignorant if there is something glaringly obvious that I am unaware of since I am just learning. Please share some wisdom with me!

 

[Vixi]

Thanks for the resource, Spatts. That was excellent info! There are several universities within a somewhat reasonable driving distance from me so I may do that when I get my weight down a little bit more. Guess I can get some calipers in the meantime.

 

[wilson6]

"Not a home use one, but one of those high end $2,500 ones."

Doesn't matter.

Get in a BodPod or have a UW weigh done, or skin folds by an experienced tech.

W6

 

[d80p]

Gender Hydrostatic % Fat Skinfold Fat Bio Imp %fat
M 35.7 14 27.9
M 39 15.5 33.5
F 42 21 28.4
F 20.21 14 44
F 21.86 17 34.1
M 40 15 21.4
M 15.5 8 15.4
M 16 8 5.1
F 33.16 17 22.1
M 22.068 10 9.9
M 24.137 12 24.1
F 20.5 18 23.2
F 23.12 12.5 19.9
M 26.8 7 9.1
F 21.5 22 32.5
Average 26.77 14.07 23.37
SD 8.85 4.58 10.60
Pearson r 0.42 (hydrostatic/skinfold)
Pearson r 0.25 (hydrostatic/bio Imp)

Sorry, the format is messed up, I was too lazy to edit.

Anyhow, these were the body fat percentage numbers for my exercise science class derived from various testing methods. As you can see, the Bio impedence % and the hydrostatic methods had a Pearson r number of .25. (No correlation) So yeah, if we assume that the hydrostatic %s were correct then we can say that bioelectrical impedence method isn't the most accurate way to test your body fat. Since we're on the topic, the fat calipers had no correlation either.

 

[VeggieLifterChick]

WHOA! Hold on a minute! You're 5'4'', 110 lbs, and you said you want to lose about 35 lbs!!!!???? So you want to weigh 75 lbs?!

How come no one commented on this!? By the way I also find it hard to believe that with those stats your bf% could be as high as you said it is.

 

[d80p]

WHOA! Hold on a minute! You're 5'4'', 110 lbs, and you said you want to lose about 35 lbs!!!!???? So you want to weigh 75 lbs?!

How come no one commented on this!? By the way I also find it hard to believe that with those stats your bf% could be as high as you said it is.

I think her FFM was 110 not her total body weight.

 

[VeggieLifterChick]

Ooooooooooohhhhhhhhhhhh! As in, Fat Free Mass? Oh good. Cuz that really bugged me out.

 

[wilson6]

"Since we're on the topic, the fat calipers had no correlation either."

They do if the right formula is used and the skinfold sites are measured accurately. Remember, skinfold formulas are based on hydrostatic weighing, but are specific for that population (i.e. same race, gender, activity level, age, etc.)

So if you used a formula derived from anorectic white chicks on black female bodybuilders, the correlation will be zero.

W6

 

[Vixi]

VeggieLifterChick - hah! No way do I want to weigh 75 lbs! That would be pretty twisted. I am working towards around 125 lbs with around 15-18% body fat.

 

[d80p]

"Since we're on the topic, the fat calipers had no correlation either."

They do if the right formula is used and the skinfold sites are measured accurately. Remember, skinfold formulas are based on hydrostatic weighing, but are specific for that population (i.e. same race, gender, activity level, age, etc.)

So if you used a formula derived from anorectic white chicks on black female bodybuilders, the correlation will be zero.

W6

Well for the numbers above they didn't correlate. So I guess I should revise my statement and say, skinfold site measurement of the average athletic white coed did not correlate with his/her hydrostatic measurement.

....I don't know what we were using as a standard for the fat caliper testing, but if you look at all of the numbers they are all off from the hydrostatic testing.