BF versus BMI calc

h3h8m3
h3h8m3 Posts: 455 Member
edited September 30 in Health and Weight Loss
Okay, so i have been trying to get a good handle on a healthy goal weight. My original goal was 250, and I am sure that's too high now. But I am not sure what a realistic goal is.

I am a 6'3 34 year old man. I have a very large frame (wide shoulders, huge head, etc). I started at 345 pounds, I'm at 261 as of today.

BMI tells me to be 199 or less for the "healthy" range. That seems way too low for my frame.

I bought a handheld body fat analyzer, and have been using it for the last 50 or so pounds of my loss. Currently it says I have 25.5% body fat. My sister has a body fat analyzer scale, and it agrees with my handheld one. I figure that if two different devices give about the same number, it's probably in the right ballpark. Per what I've read a healthy body fat % for my age would be between 8-19%.

Assuming my body fat is 25.5%, that means I have 194.45 pounds of non-fat, and 66.55 of fat.

I've noticed as I lose weight that my body fat doesn't go down at a level equal to the total amount of pounds I'm losing... when I was at 300 pounds, it said I had about 30% body fat, which would be about 210 non-fat pounds. So I'm losing some pounds other than fat.

All of this to say... any ideas what my goal weight should be? Yes, in the end it will come down to how I look, and how I feel, not a number on a scale. But one of the things that's made me successful in this new lifestyle is my detailed planning, and my manic-level commitment to details. So while I can understand the "don't worry about, you'll know when you get there" answer, it's not really what I'm looking for.

Thanks in advance for your time.

Replies

  • aj_rock
    aj_rock Posts: 390 Member
    At your size, you will lose lean mass as well as body fat. It's not all muscle and whatnot; lots of organs in your body grow very large in size to accomodate your large size as well.

    For example, your heart is probably much larger than most hearts of people of your height, in order to pump blood through more tissue.

    This lean mass will drop as well, so if you continue to diet, you could at least get *close* to that ideal range.

    drop another ten pounds or so and re-evaluate. Continue testing your BF% though.
  • vim_n_vigor
    vim_n_vigor Posts: 4,089 Member
    Ignore BMI.
  • baisleac
    baisleac Posts: 2,019 Member
    Ignore BMI.

    This. And check out if any gyms in your area offer free or low cost caliper body fat testing (or better yet a BodPod). The handheld ones are notoriously inaccurate for anything except relative change.
  • run_momma_run
    run_momma_run Posts: 319
    Those types of BF calculators are just an estimation. If you want a more accurate assessment, you should make an appointment with a personal trainer or physiotherapist and have a body compisition test done. With the calipers, you'll get a better handle on the number. And then that person can also accurately tell you what a good weight range would be for your body type, too.

    My guess would be that a healthy goal range for you would probably be 210 - 230.
  • jdoggie
    jdoggie Posts: 42
    I think it definately comes down to how you feel, But I would say 215-220 I have a son who sounds like he is built like you, My other two are tall as well, but not as thick, and i don't mean fat, he is just a thicker build, he is in good shape and goes inbetween those wieghts depending on the season, I think it is healthy and safe. not sure if that helps. Have a great day:)
  • iTim__
    iTim__ Posts: 6,823 Member
    I use the "Devine" formula to figure out ideal weight for me. If you're a serious body builder, then this wouldn't work for you. But, it has worked for me. I've been able to overcome some health issues (like high glucose levels, cholesterol levels, and high blood pressure -- all gone now). Of course, weight is only one part of the picture, but it is a big part of it.

    According to the Devine formula, it would recommend an ideal weight of 186 lbs. http://www.halls.md/ideal-weight/body.htm

    By the way, I had always said I have a "big frame" too. For me though, after loosing the weight, I realized that is something fat people say to justify their weight -- I base that on the fact, I said and believed it about myself. I read an article that said, you should put your index finger and thumb around your wrist, if there's a gap between them, you've a large frame. If they touch or almost touch, you've a medium frame. If they overlap, you've a small frame.
  • shydaisi
    shydaisi Posts: 788 Member
    Keep in mind that you do lose some water weight as you reduce in size.

    I lost a lot of weight before (88 lbs) and went from size 22ish to a size 6. I had always been big and just thought that I had a large frame. I was surprised at how much smaller my frame was than I had thought, but I couldn't see that until the weight was gone. It is possible that your frame is a little smaller than you think and that lower weight range might work for you!
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    The formula we use in our Exercise Physiology program to determine ideal weight is based on the desired body fat percentage and current lean body mass. If you exercise properly, you don't lose lean body mass while losing fat. You may lose water weigh, which shows up on a body composition analysis as lean body mass, but you won't lose muscle if you are using it and you won't lose bone if you are getting adequate nutrient intake (IE: calcium), and you won't lose organ size. If you aren't weight training, you may lose muscle mass, but that is mostly water from loss of glycogen storage, not actual fiber loss. You will lose muscle fibers if you are having to break down the protein in them to form glycogen to be able to burn body fat, but that is only from lack of adequate carbohydrate intake. Anyway, my point is that you can maintain your lean body mass while losing body fat, so a formula to determine ideal body weight based on your current lean body mass and a goal body fat percentage is much more accurate for each individual then the BMI or ideal weight charts that MD's use because they aren't based on lean vs. fat in the individual. Anyway, here is the formula:

    Lean Body Weight / (1 - BF% desired in decimal form) = Ideal Body Weight

    So, if you are currently 194.45 of lean body mass and want to be 19% body fat, it would look like this:

    194.45 / (1 - 0.19) = 194.45 / 0.81 = 240 pounds

    If you want to get to 8% body fat, it would look like this:

    194.45 / (1 - 0.08) = 194.45 / 0.92 = 211 pounds

    Obviously you can pick any goal body fat % in the healthy range and get a more accurate estimate based on what you want.
  • h3h8m3
    h3h8m3 Posts: 455 Member
    Ignore BMI.

    This. And check out if any gyms in your area offer free or low cost caliper body fat testing (or better yet a BodPod). The handheld ones are notoriously inaccurate for anything except relative change.

    I've been checking around for a water BF place around Denver, but haven't seen one yet. I'm keeping an eye open though. I am not interested in the caliper test as everything I have read is that they're as unreliable as the handheld and scale BF analyzers, and completely subject to the experience/skill of the person using them. That said, having another piece of data can't hurt, and getting their read on it would give me another tool in the toolbox.
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    Ignore BMI.

    This. And check out if any gyms in your area offer free or low cost caliper body fat testing (or better yet a BodPod). The handheld ones are notoriously inaccurate for anything except relative change.

    I've been checking around for a water BF place around Denver, but haven't seen one yet. I'm keeping an eye open though. I am not interested in the caliper test as everything I have read is that they're as unreliable as the handheld and scale BF analyzers, and completely subject to the experience/skill of the person using them. That said, having another piece of data can't hurt, and getting their read on it would give me another tool in the toolbox.

    Check with your local colleges and see if they have an exercise science department. They may have the equipment to do a Bod Pod (what we use at my school) or hydrostatic weighing. Also, you can check with your doctor or the local hospital about a DEXA scan, which is the new gold standard in body composition analysis.
  • h3h8m3
    h3h8m3 Posts: 455 Member
    The formula we use in our Exercise Physiology program to determine ideal weight is based on the desired body fat percentage and current lean body mass. If you exercise properly, you don't lose lean body mass while losing fat. You may lose water weigh, which shows up on a body composition analysis as lean body mass, but you won't lose muscle if you are using it and you won't lose bone if you are getting adequate nutrient intake (IE: calcium), and you won't lose organ size. If you aren't weight training, you may lose muscle mass, but that is mostly water from loss of glycogen storage, not actual fiber loss. You will lose muscle fibers if you are having to break down the protein in them to form glycogen to be able to burn body fat, but that is only from lack of adequate carbohydrate intake. Anyway, my point is that you can maintain your lean body mass while losing body fat, so a formula to determine ideal body weight based on your current lean body mass and a goal body fat percentage is much more accurate for each individual then the BMI or ideal weight charts that MD's use because they aren't based on lean vs. fat in the individual. Anyway, here is the formula:

    Lean Body Weight / (1 - BF% desired in decimal form) = Ideal Body Weight

    So, if you are currently 194.45 of lean body mass and want to be 19% body fat, it would look like this:

    194.45 / (1 - 0.19) = 194.45 / 0.81 = 240 pounds

    If you want to get to 8% body fat, it would look like this:

    194.45 / (1 - 0.08) = 194.45 / 0.92 = 211 pounds

    Obviously you can pick any goal body fat % in the healthy range and get a more accurate estimate based on what you want.

    Great post Tanya, thank you very much.

    I was assuming something like that, but as I've said, I have been losing lean weight as well as I go, and don't know how much more of it I can expect to lose.

    I do strength training 3x a week, mostly body weight exercises (pushups, situps, pullups, arm haulers, squats, lunges, plank, leg raises, etc), and I can see a pretty big improvement in my strength as I do them. So I am fairly confident that I am at least maintaining my muscle. I also go for 40% protein in my diet, and make sure to protein up after my strength workouts.

    A range of 211-240 sounds pretty good as "healthy" for me. I could see it being a bit lower, like 205-235. Fully clothed I look okay now, but without a shirt... it's still not pretty.
  • h3h8m3
    h3h8m3 Posts: 455 Member
    never mind
  • TrainingWithTonya
    TrainingWithTonya Posts: 1,741 Member
    The formula we use in our Exercise Physiology program to determine ideal weight is based on the desired body fat percentage and current lean body mass. If you exercise properly, you don't lose lean body mass while losing fat. You may lose water weigh, which shows up on a body composition analysis as lean body mass, but you won't lose muscle if you are using it and you won't lose bone if you are getting adequate nutrient intake (IE: calcium), and you won't lose organ size. If you aren't weight training, you may lose muscle mass, but that is mostly water from loss of glycogen storage, not actual fiber loss. You will lose muscle fibers if you are having to break down the protein in them to form glycogen to be able to burn body fat, but that is only from lack of adequate carbohydrate intake. Anyway, my point is that you can maintain your lean body mass while losing body fat, so a formula to determine ideal body weight based on your current lean body mass and a goal body fat percentage is much more accurate for each individual then the BMI or ideal weight charts that MD's use because they aren't based on lean vs. fat in the individual. Anyway, here is the formula:

    Lean Body Weight / (1 - BF% desired in decimal form) = Ideal Body Weight

    So, if you are currently 194.45 of lean body mass and want to be 19% body fat, it would look like this:

    194.45 / (1 - 0.19) = 194.45 / 0.81 = 240 pounds

    If you want to get to 8% body fat, it would look like this:

    194.45 / (1 - 0.08) = 194.45 / 0.92 = 211 pounds

    Obviously you can pick any goal body fat % in the healthy range and get a more accurate estimate based on what you want.

    Great post Tanya, thank you very much.

    I was assuming something like that, but as I've said, I have been losing lean weight as well as I go, and don't know how much more of it I can expect to lose.

    I do strength training 3x a week, mostly body weight exercises (pushups, situps, pullups, arm haulers, squats, lunges, plank, leg raises, etc), and I can see a pretty big improvement in my strength as I do them. So I am fairly confident that I am at least maintaining my muscle. I also go for 40% protein in my diet, and make sure to protein up after my strength workouts.

    A range of 211-240 sounds pretty good as "healthy" for me. I could see it being a bit lower, like 205-235. Fully clothed I look okay now, but without a shirt... it's still not pretty.

    Body weight exercises do maintain muscle fibers, but they don't promote as much glycogen storage in the muscle so you won't get the body builder pump look from that type of exercise, which is fine as long as you aren't a competition body builder. ;) The difference in weight is then from the loss of glycogen and the water it is stored in since you aren't needing to maintain the super high glycogen storage that body builders need. Because it is glycogen and water and not fat, it will be read as Lean Body Mass when you do a body composition analysis. So, yes, you're losing lean body mass, but you aren't really losing muscle. Make sense? That should level off though as your body settles into its set point where glycogen storage = glycogen need. When you get there, you'll see a lot less lean body mass (glycogen and water) loss.
  • h3h8m3
    h3h8m3 Posts: 455 Member
    Body weight exercises do maintain muscle fibers, but they don't promote as much glycogen storage in the muscle so you won't get the body builder pump look from that type of exercise, which is fine as long as you aren't a competition body builder. ;) The difference in weight is then from the loss of glycogen and the water it is stored in since you aren't needing to maintain the super high glycogen storage that body builders need. Because it is glycogen and water and not fat, it will be read as Lean Body Mass when you do a body composition analysis. So, yes, you're losing lean body mass, but you aren't really losing muscle. Make sense? That should level off though as your body settles into its set point where glycogen storage = glycogen need. When you get there, you'll see a lot less lean body mass (glycogen and water) loss.

    Another great post. Thanks again Tonya.
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