100 lb. Club - Interesting talk with RD (or why the BMI lies)

01-17-2003, 01:29 PM
I went to see my dietician yesterday, and I was saying how my weight loss seems to be slowing down and that is discouraging to me because of how much weight I have left to lose. So she was asking me what weight I was using as my goal . . . I said 135 (I'm only 5' 4"). She looked at me and said, "that seems a little low. Let's see what I have as your goal." I'm thinking, what?! 135 low for someone who's 5'4"? She said that her goal for me is 175.

She then went on to explain that when someone is overweight, 25% of the extra weight is muscle (allowing the person to move about, even with the extra fat). So using 120 as the "ideal" weight for someone my height, she added 25% of the excess weight I had when I started ((starting weight - ideal weight) * 25%) and calculated my "revised ideal" weight at 175.

If I weigh 175, my BMI will still put me in the "obese" class. But I'll be in good company . . . Arnold Schwarzenegger's BMI is 33 (obese).

I don't know, it makes sense, but I still would like to be a "normal" weight (for once in my life). So I'm thinking I'll try for 145, which would be the highest I could go and still fall into the BMI normal range. But then again, maybe I'll be happy at 175. I guess I'll wait and see.

01-17-2003, 02:10 PM
yeah, righ tnow my goal is so far away that i really have no idea whether i'll be satisfied with it, you know? so it's at 160, which is in the healthy weight range for being 5'7", but when i get there, i'l have to re-evaluate. i think that's what a lot of us will have to do.

01-17-2003, 02:36 PM
I'm very confused by BMI charts and comparing weight with other people in general.

Over the holidays, when my in-laws were here, my mother-in-law asked to borrow the scales. She is pretty young (49 - my DH is nine years younger than I!) and has lupus. She had lost a lot of weight and everyone was really worried. So, she thinks she's gained it back but wanted to know for sure. So, here this tiny little woman - who is wearing the Size Small sweater I bought her for Christmas - standing on the scales and they say "129." She's 5'5'' - the same height as me. I was shocked. How does this tiny person weigh that much?

She's a size 6.

When I weighed my lowest adult weight - 133 - I was a size 10 - and a Medium.


I was encouraged though. I've sort of thought my goal of 150 was a little high. But now I think it's fine. Everybody's different.


01-17-2003, 02:52 PM
whoa. This puts my ideal weight at 187 lbs. Wow.

01-17-2003, 03:18 PM
That puts my ideal weight around 185 too. I can't hardly remember what it was like being 185lbs, let alone 165. If I feel good at 175 or so, I'll stay there. I'm 5'9" and back when I did weigh 190 (way back when lol), I was only 5'6", so I have nothing to compare it to. :) My BMI was 39 when I started my weight loss, and now it is 30.

01-17-2003, 03:26 PM
That is too much math for me. But I think the BMI is more & more like the old height & weight tables--a standard that might not work for everyone.

I will try the math later when I have more time. (Lunch is loooong over)

01-17-2003, 10:10 PM
wow!!!!! i had no idea!!!! is this why the docs are telling me not to lose too much weight when i tell them i want to get down to between 170 and 180??? do they actually KNOW something useful???!!!!!

if this is right - and THAT's a real cheery thought - i have less than 50 pounds to go!!!!!!

01-17-2003, 10:40 PM
Okay maybe I am doing something wrong.

((Start weight - ideal weight) * 25%) doesnt seem correct cause
((231-122)*0.25)= 27.25

Now I can derive two formulas from what you said
1. I am given a 25% muscle mass just for being fat(?-I question this a little bit because though I understand the nutriotnist point that when you are overweight sometimes moving your body is a weight lifting excersise, overall % body fat/muscle varies) 231(start weight*0.25(% muscle) = 57.75 lbs. of muscle + ideal weight = 179.75

2. ((231(sw)-122(iw)+((231(sw)-122(iw))* 0.25))=136.25

Either way BMI doesn't work for people with muscle (ie. the Arnold S. example), large bone structures, small bone structures, women who pregnant, nursing, people who have metal plates in their skull ;-) and the list goes on.

I think that setting the mini-goals and re-evaluating for general health is the most useful along the way. I have set a goal off 122 lbs. for myself. But I also know I am pretty strong and I continue to work to build muscle, so the first time I can find an impedence weight I will probably adjust that goal to reflect actual body fat.

Sorry to be so analytical, I guess that is just the chemist in me coming out!

Miss Chris

01-18-2003, 12:14 AM
Holy carp! I think I want Miss Chris to do my math. :D I couldn't figure out the formula until her post. So, thank you, dolly!

According to that, my ideal weight is 207. That's a more attainable goal than 150, but as I lose the weight, I have a feeling that it won't be about numbers on a scale or a BMI number or anything else. It'll be more about the way I feel, how my clothes fit on me, how active I am, etc.

Thank you for posting this, Jo. It made me think.

01-18-2003, 05:25 AM
Here's how I did the math
Starting Weight...........................262
Ideal Weight...............................120
subtract that..............................._________
Excess weight of ........................142
Times by.......................................x25%
Equals.........................................___ _________
.................................................. ...35.5
Add to Ideal W. ...........................120
Equals a new Ideal weight of:
.................................................. ..155.5 lbs...

01-18-2003, 09:27 AM
i like amy's math, which matches ro's formula 2 ... but i started out at 500 pounds. and my ideal weight is 150, a difference of 350 pounds. 25% of that is 84 pounds, and there's just no way my revised ideal weight could possibly be 235!!! that's just 10 pounds away right now. and i'm about a size 18/20 [maybe a little smaller, but not much]

but at least this shows that my ideal weight could be a bit higher than the 150, a weight at which i feel exhausted, sluggish, feeble.

the adventure continues!!!!

01-18-2003, 12:48 PM
Using the formula, my ideal weight is 133.75. My goal is 135, so I guess I'm one of the few for whom the formula works.

01-18-2003, 02:08 PM
About a year or so ago, I had my body fat tested is a pretty reliable manner. My lean body mass was 170 lbs, which is 20 lbs or so more than the high end of the "normal" BMI.

So my goal weight is 200 right now.

01-18-2003, 04:39 PM
Hey Jenelle,
How are you doing your math? When I figured it out using 238 as a starting weight, with an ideal weight as 135, I came up with 160.75.


I don't know what your start weight was, or what the ideal weight for your height is, but maybe you should try again?

Nicole :)

01-18-2003, 05:03 PM
Nicole -

I actually used my all-time high weight of 242.5, which I rounded up to 243.

243-135 = 108
108 x .25 = 27
108 + 27 = 135

The formula is (starting weight - ideal weight) X 25%. Your math mistake was adding the 25% to the ideal weight, rather than to the difference between starting weight and ideal weight.

01-18-2003, 05:22 PM
Well Jennelle, if I do my math the way you do I get 177.5 which is not too bad of a goal for me as well.... (it's a quicker goal in any case... :-) )

01-18-2003, 06:35 PM
Well what I don't get is, as you lose the weight you will also lose muscle, almost impossible not to, especially as when you get smaller you won't need so much to lift and carry you etc, muscle not used doesn't stay muscle for very long. Besides if this didn't happen you would see all these large muscley ppl at goal weight after they had lost the weight. When I see after pics I just see normal looking ppl. Maybe she meant a healthy range for weight is different then ppl that have never had a weight problem? I'd like to be able to be slim not big and muscley after I finish.


01-18-2003, 07:59 PM
Well most women can't be big and muscly no matter what they do. Muscle is very lean and compact and very easy to lose. If for some reason that is a problem, its easier to tackle the fat first then worry about other stuff later. I can't imagine there being a woman body builder somewhere hidden under my fat ;) I know I have a lot of muscle in my legs though that supports my weight.

01-19-2003, 03:29 AM
Very interesting ... I'm not EVEN going to worry about trying to do that math. I keep signing my goal as 150ish, but in truth I figure I will just keep going until I get to where I feel good and like the way my body looks. If it's 170 ... well, heck, that's only about 50 more pounds!

265/218.5/150ish or whatever!