So I was thinking about body composition and decided to run some numbers. My conclusions were pretty startling.

I've had my body fat taken 3 times using bioelectrical impedance. All three of these taken at school under similiar conditions (in clothes but minus shoes).

Humiliating forced weigh-in, spring 8th grade (14 y.o.)- 135lbs, 40% body fat ~5'1.5"
Sophmore PE, beginning of semester (15 y.o.)- 99lbs, 15% body fat ~5'2"
Sophmore PE, end of semester (almost 16)- 99lbs, 13.5% body fat

Please note: Having a body fat percentage that low is not recommended for women. My lowest recorded body fat was a little lower than what's considered normal for athletes. My general practioner said I was fine because I had great lean muscle mass and experienced no adverse indicators (loss of period, hair and skin issues, etc.). In other words, do not attempt.

Obviously I lost 36lbs+ in that period, which I already knew. My estimated lean body mass was only 81lbs in the 8th grade. That means I was carrying an estimated 54lbs of fat! What's more interesting to me than just the weight loss is that in the same period I added 5lbs of lean (non-fat) body mass. That means that teenage me was able to lose 41lbs of body fat by eating less and exercising more.

Now on to the bad news: I'm now in my mid-20s, and I'm definitely no size 0 anymore. I'm an extreme hourglass shape, so while my waist is a 6, my bust and hips are a 10 (based on the Gap's size charts). Although I've been exercising almost everyday for a couple months, I'm still a good 10lbs+ off from where I should be.

So what should I weigh? This was the orginal question that inspired me to run the numbers. First, I estimated my current lean body mass to be about 95lbs. I'm somewhere around an inch and a half taller than I was my sophmore year of high school. I've been lifting so I've probably add a little bit of muscle as well though I can't really lift any more than I did in high school. So here's the really terrible news: my ideal condition would probably be somewhere around 115lbs (20% body fat). An acceptable and more attainable weight for me would be around 125lbs. The most I should weigh would be around 130lbs as I highly doubt that I have more than 100lbs of lean body mass. I really have no idea how much I currently weigh, but I know it's more than 125. This is all depressing.

Do any of you know (or have a reasonable guess) what your lean body mass is? Is body fat a factor for you or are you more focused on weight or size or fitness level or how you look?

I've never had my lean body mass measured, but when I try different online calculators and plug in my measurements, I get anywhere in the vicinity of 17-23% body fat. Seems about right I guess since I can fit into some size 2 pants at 132 pounds.

I focused a lot on weight on the way down, but I did have a size goal. It was a size 6. Unfortunately when I got there I was still unhappy! I've never been at a normal weight so I had no idea what I would look like. I kept going and wound up getting down to a 2/4. I'm still not completely satisfied with my body, but I don't really want to get any smaller. My ribs are sticking out a little (I'm large-framed. I'm pretty much at the lowest someone my height and build should weigh).

I've sort of got a similar issue to you in that my hourglass shape causes me some difficulty in clothes. Luckily my waist recently went down to 26", meaning that my waist and hips are a 2/4, but my bust is 37" which puts me in an 8/10. Annoying, but I'm looking at some of the online retailers who cater to ladies with ample bosoms



If focusing too much on weight depresses you, then focus on size! Do you have a size goal or an ideal size in mind? There is no need to get yourself stressed out over a number on the scale.

The only way to get an idea of lean body mass is to have another impedence test. You can buy a bathroom scale that does the same thing that the ones you used with bare freet did. Tanita is a good brand.

Beware of averages, because that's all they are. I have come to the conclusion that life cannot be lived by numbers and statistics. Most of the "calculations" I've seen on the web give rather low numbers for "ideal weight"--and they don't apply to everyone.

That said, I think body fat % is a good measure to go by, as long as you take it with a grain of salt. The only really accurate way to measure this is with immersion testing, and it's expensive. I use body fat % just to make sure I'm losing more fat than lean body mass when I'm losing weight.

But, mostly these days my goal is more along the lines of lifestyle. I've been around this block enough times to know that I don't want to exercise at the gym 6 days a week and eat really low calorie just to maintain a scale number. I'd rather go to the gym 3-4 times a week and eat moderately.

Jay

Like Jay says above, the only way to know is to measure. It's best not to guess, because normally you will not even be close. When I first started measuring my body fat % I didn't really understand what it meant. Now that I understand it, it's very simple.

I use an Omron scale that has the hand held part that gives me a surprisingly accurate account for what it is. I've also used the 7-point caliper measurement to corroborate the scale when I first started using it. Calipers take a while to get used to and learn how to do it accurately.

So for me, I weigh 250.2 pounds and have 32% BF. I'm 6' 2" tall so I have a lot of lean mass as well. So 32% of 250.2 is about 80 lbs. so I have 80 lbs of body fat. Yes, that's a big fourth grader. So 250.2 minus 80 lbs of fat is 170.2 lbs of lean body mass. I know that I can't get to 0%, and you alluded to it as well above, it's not healthy for a person to get too low and it's VERY difficult to maintain. My goal is 8%. So 8% of 170.2 is about 13 lbs, give or take a few ounces. So my "goal weight" would be around 183.5 lbs. At 2 lbs of healthy weight loss per week that will take me around 33 weeks if I never stray and never hit a plateau. Both are unlikely. Now, since I do plan to work out quite a bit my lean mass will likely change. The more lean mass you have the more calories you burn at rest and at play. If I don't eat properly it can change for the worse. If I eat properly and work out properly it will probably stay about the same and may go up a little. You have to have a caloric surplus to gain mass. I'm hoping to be in caloric deficit for some time.

Everyone is different and a lot of the work is figuring out the best path for you. I think people should shoot for healthy body composition, not necessarily a set weight. Weight may not be a good indicator of health. As always, this last is my opinion and should be taken with a grain of salt. YMMV.

Drew

I'm no expert, but I like to use multiple "checkpoints" to determine my healthy goal weight.

1.) actual desired weight range (125-128)
2.) desired pants size (2-4)
3.) body fat %, checked with calipers (18-22%)

By using all three of these "checkpoints" it is more likely I will be able to maintain. what freaks me out, is that the scale number really doesn't matter. You could get to your goal weight, stop working out as hard, and actually get "bigger" staying at that same weight.

Sounds like me. I've also used multiple checkpoints. I don't have access to someone who knows how to use calipers (I wish!!!) but I have other goals

1. Healthy BMI (under 155lbs)
2. 28" waist
3. size 8 or under (already there but since I was thinking of the size 8 in high school, well, who knows what size that translates into today!)

Once I get under 155lbs pretty much I'll reevaluate and see how much farther I want to go. I've been 140lbs (and was very happy there) before but without weight lifting so that's the lowest I plan on going. Otherwise I don't have a set number in mind.

If you really want to get your body fat % measured try and find someone with calipers that's well trained in how to use them.