Body Fat and Lean Body Mass math

megruder

Ok, I'm a newb and a couple months ago guesstimated my goal weight at somewhere between 170-180, probably re-evaluate when I get closer. I've done some research and I'm a little confused. I'm 5'3" and currently 250 lbs, already lost 28. According to the BMI scale I should be somewhere between 120-140. I know that BMI is not the most accurate scale for numerous reasons.

Now, I recently had my body fat percentage measured using a couple different methods (tape measure and calipers) and got somewhere between 40-44%. If I go with the higher percentage that leaves me with body fat weight of 110 lbs. (I know it's high, but it doesn't depress me since I've already lost 20% of my body fat. Yes, I can do math.) Ok, that leaves me with a lean body mass of 140 lbs, which is already at the high end of the BMI scale for my height. A healthy body fat percentage range for women puts me right in the 170-180 lbs range. All this assumes that I DON'T gain any more muscle as I weight train (I DO want to gain muscle) and lose weight.

So, am I way off or does this all make sense? Is it normal to have that much lean body mass? If I lose the remaining weight in a healthy way, will I also lose some of my lean body mass? I've always thought of myself as having a larger frame, but even with that in mind according the various web calculators my ideal weight should still be under 148 lbs. The only way I can even get that low mathematically is if I allow for a 5% error on my body fat percentage (giving me 49% body fat) and adding 21% body fat to a lean body mass of 122.5 lbs for an ideal weight of 148.225 lbs.

I know I'm probably making more of this than necessary, but I'm a little geeky and like hard numbers. I also keep seeing all these short women with weight goals of 120-130s and I feel like I'm just so far off base.

shadow3829

I would try some of the one line calculators. Something is not quite right. 49% body fat is not in the healthy range for a 5'4" women.

Fitness 21-24%
Acceptable 25-31%
Obeses 32% or more

These are the American Council for Exercise standards.

megruder

I guess I wasn't quite clear in the last sentence with math. I was saying that with a 5% error in my CURRENT body fat percentage it could be 49%. That would decrease my lean body mass to 122.5 lbs. Now tacking on a low, healthy body fat percentage of 21% would still put my ideal body weight at 148 lbs.

Without any measurements I KNOW my current body weight/composition is NOT healthy. I'm just trying to figure out a realistic, ideal goal weight and according to the math that seems to be in the 170-180 range. I guess I'm just having difficulty wrapping my head around that being an ideal weight for a 5'3" female. Everything I've read says I should be under 140.

xraychick77

if you dont cut cals so drastically, and if you continue weight training you wont lose muscle mass or lean body mass. lean body mass includes everything but fat basically..your organs, skeleton and muscle. last i measured my body fat was 22%..i'm 120 lbs 5'2". i want to get a little lower, since i'm looking to get cut and have lots of muscle definition.

go to bodybuilding.com and you'll see shorties with even lower weight than that, but they look far from skinny they look built..i dont know how they do it, but i guess they've lost so much fat and made up for it in muscle it evens out. i'm talking they weight like 110-115 lbs.

you shouldnt just go on weight..since muscle by volume weighs more than fat. you should really just judge based on body fat percentage. i'm looking to get into the teens of body fat...my next goal is 20% then 17% and i'll see how i look from there.

p.s..you probably have a significant amount of muscle on you..i'm not trying to be mean or crude, but the larger a peson is the more muscle mass they usually have..and i'm sorry and i really apologize, i dont mean to sound mean or anything..but the larger a person is, the more muscle it takes to move them around, hence the more muscle mass they usually have. so in your case probably a much higher percentage of your weight 250lbs, is already muscle. so you techincally are at an advantage as far as getting muscle and looking built. cuz after you lose the fat, you'll already have a lot of muscle to show off!

WolffEarl

Hi there.
Your math looks solid. Assuming you are currently at 250, and your BF is indeed right around 44%, that does give you a lean body mass of 140 lbs. Now add 23% Body fat to that (which is in the healthy range for women) it does indeed put you right at 180 lbs. Now this may seem quite high for someone of your height, but many factors impact the ideal weight calculations (frame, bone density, existing muscle mass, etc). I am not sure how accurate the measurements are you had taken or took yourself. I hear that even calibers can be very tricky. Sometimes the mirror can be the best answer, and of course your ability to do various exercises.

arewethereyet

In my humble opinion, it is way too early to be worring of such things for you.

Once you have lose enough weight to get in 'range' of where you want to be when you look in the mirror, weight will mean nothing to you.

I have friends my height and weight (5'2" 143 lbs) that are in a great BF %. I also have friends in my height range who weigh below 130 and look 'fatter' than me (and are def less healthy given their lifestyle, but that is a diff thread!)

Right now it is all about you learning about food, exercise and the long term of keeping these things in the forefront of your mind.

When you get down to 160 or so you will be able to knwo where you want to go from there.

Congratulations on your success!!! :flowerforyou: