![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 15 of 15. This is the beginning of the thread.
Posted by Deneb on October 22, 2006, at 17:46:41
Dr. Bob,
Are you sure that your BMI calculator is correct?
Most calculators say that anything below 18.5 is underweight. Some say it's under 19, but yours says under 20 is underweight.
Which number is correct?
The proposed age-corrected BMI determination seems correct though.
Deneb*
Posted by Dr. Bob on October 23, 2006, at 21:15:01
In reply to About the BMI calculator, posted by Deneb on October 22, 2006, at 17:46:41
> Most calculators say that anything below 18.5 is underweight. Some say it's under 19, but yours says under 20 is underweight.
Hmm, interesting. Who decides what's considered "underweight", did you come across that?
Bob
Posted by fayeroe on October 23, 2006, at 23:59:40
In reply to Re: About the BMI calculator, posted by Dr. Bob on October 23, 2006, at 21:15:01
> > Most calculators say that anything below 18.5 is underweight. Some say it's under 19, but yours says under 20 is underweight.
>
> Hmm, interesting. Who decides what's considered "underweight", did you come across that?
>
> BobWho sets the BMI standards?
A: Medical professionals most often use BMI instead of height/weight charts when studying the effect of body weight on health. 7
In 1995, the World Health Organization recommended a classification for three "grades" of overweight using BMI cutoff points of 25, 30, and 40. The International Obesity Task Force suggested an additional cutoff point of 35 and slightly different terminology.
In 1998, two organizations within National Institutes of Health -- the National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases -- put together an expert panel who released a report with definitions for overweight and obesity in agreement with those used by the World Health Organization.
Thresholds
Given the reservations detailed below concerning the limitations of the BMI as a diagnostic tool for individuals, the following are common definitions of BMI categories:Starvation: less than 15
Underweight: less than 18.5
Ideal: from 18.5 to 25
Overweight: from 25 to 30
Obese: from 30 to 40
Morbidly Obese: greater than 40
The U.S. National Health and Nutrition Examination Survey of 1994 indicates that 59% of American men and 49% of women have BMIs over 25. Extreme obesity — a BMI of 40 or more — was found in 2% of the men and 4% of the women. There are differing opinions on the threshold for being underweight in females, doctors quote anything from 18.5 to 20 as being the lowest weight, the most frequently stated being 19. A BMI nearing 15 is usually used as an indicator for starvation and the health risks involved, with a BMI <17.5 being one of the DSM criteria for the diagnosis of anorexia nervosa.
Posted by Deneb on October 24, 2006, at 0:04:33
In reply to Re: About the BMI calculator, posted by Dr. Bob on October 23, 2006, at 21:15:01
> Hmm, interesting. Who decides what's considered "underweight", did you come across that?
>
> BobI did a preliminary search and did find one article in the Canadian Medical Association Journal that wrote 20-25 was normal BMI.
Bob, there are a LOT of medical journals. If they have different figures I have no idea how to figure out who's right and who's wrong.
There probably isn't a definite number in reality. I think people can be underweight with different BMI's. It all depends on body composition. I'm guessing they figure out what underweight is by figuring out at what BMI people have increased health problems or something. There's probably some magical cut off figure between healthy and unhealthy. Maybe it's based on % mortality, who know?
If I have free time and I feel like it I will do some research on this.
Deneb*
Posted by Deneb on October 24, 2006, at 0:09:08
In reply to Re: About the BMI calculator, posted by fayeroe on October 23, 2006, at 23:59:40
Thank-you fayeroe!
That was very informative!
See Dr. Bob, I told you so. LOL
Deneb*
Posted by Deneb on October 24, 2006, at 0:21:54
In reply to Re: About the BMI calculator, posted by Dr. Bob on October 23, 2006, at 21:15:01
Oh Bob, I love you so. :-)
You're sandwiched between fayeroe and me. Aww.
((((Dr. Bob))))
Thanks for writing.
Dr. Bob, did you know all those things about BMI?
I knew that 19.5-24.9 was ideal. I knew above 25 was overweight. I knew below 17.5 is a criteria for anorexia. I didn't know about 15 being starvation level. I didn't know greater than 40 was morbidly obese (but I could have guessed).
Deneb*
Posted by fayeroe on October 24, 2006, at 0:35:44
In reply to Re: About the BMI calculator » Dr. Bob, posted by Deneb on October 24, 2006, at 0:21:54
> Oh Bob, I love you so. :-)
>
> You're sandwiched between fayeroe and me. Aww.
>
> ((((Dr. Bob))))
>
> Thanks for writing.
>
> Dr. Bob, did you know all those things about BMI?
>
> I knew that 19.5-24.9 was ideal. I knew above 25 was overweight. I knew below 17.5 is a criteria for anorexia. I didn't know about 15 being starvation level. I didn't know greater than 40 was morbidly obese (but I could have guessed).
>
> Deneb*AND the first time this came up, was from medical doctors, in the 1800s........i'm surprised that Bob didn't have this in medical school.
Posted by Jost on October 24, 2006, at 13:16:20
In reply to Re: About the BMI calculator, posted by fayeroe on October 24, 2006, at 0:35:44
Just saw a poster on a bus stop in NYC, looking for volunteers for a study on eating habits, at St. Luke's Roosevelt Hospital.
Said they wanted volunteers between ages of 18-35, with normal BMI (19-27).
So it's probably a general range, with some variations, 19/20-25/27 or so.
That's one instance.
Jost
Posted by Dr. Bob on October 24, 2006, at 20:12:28
In reply to Re: About the BMI calculator, posted by fayeroe on October 23, 2006, at 23:59:40
> In 1995, the World Health Organization recommended a classification for three "grades" of overweight
>
> In 1998, two organizations within National Institutes of Health ... put together an expert panel who released a report with definitions ... in agreement with those used by the World Health Organization.
>
> the following are common definitions of BMI categories:
>
> Underweight: less than 18.5So the WHO and the NIH didn't define underweight, but the above is a common definition?
Bob
Posted by fayeroe on October 24, 2006, at 22:08:35
In reply to Re: definitions, posted by Dr. Bob on October 24, 2006, at 20:12:28
> > In 1995, the World Health Organization recommended a classification for three "grades" of overweight
> >
> > In 1998, two organizations within National Institutes of Health ... put together an expert panel who released a report with definitions ... in agreement with those used by the World Health Organization.
> >
> > the following are common definitions of BMI categories:
> >
> > Underweight: less than 18.5
>
> So the WHO and the NIH didn't define underweight, but the above is a common definition?
>
> Bobthere are many websites where you can research it and find out all there is to know about BMI. it's fairly common knowledge.
most all medical trials ask for your BMI and then ask your weight and height.....they won't go under and they don't go over. they are very picky about it.
there is one new opinion that the BMI isn't as important as it was once thought to be, but i've not seen anyone else jump on that guy's bandwagon.
it's super easy to find out all you want to know on the internet about it, bob.
Posted by gardenergirl on October 24, 2006, at 22:49:25
In reply to Re: definitions » Dr. Bob, posted by fayeroe on October 24, 2006, at 22:08:35
Regardless of what standard is used for the calculator here, I think it's important for folks to check with his/her own physician about what weight and/or BMI is appropriate.
gg
Posted by NikkiT2 on October 25, 2006, at 3:31:58
In reply to Re: definitions » Dr. Bob, posted by fayeroe on October 24, 2006, at 22:08:35
>>there is one new opinion that the BMI isn't as important as it was once thought to be, but i've not seen anyone else jump on that guy's bandwagon.
The UK is strarting to follow the "BMI isn't important" idea.. My GP's no longer use it, and neither does my pain consultant
Nikki
Posted by Racer on October 26, 2006, at 13:22:57
In reply to Re: definitions » fayeroe, posted by NikkiT2 on October 25, 2006, at 3:31:58
> >>there is one new opinion that the BMI isn't as important as it was once thought to be, but i've not seen anyone else jump on that guy's bandwagon.
>
> The UK is strarting to follow the "BMI isn't important" idea.. My GP's no longer use it, and neither does my pain consultant
>
> NikkiThere's actually an awful lot on the internet saying that BMI is misleading if you use it as anything other than a convenient starting point. Athletes will have a much higher BMI than an average person, for instance, and yet they'll hardly be "overweight."
The BMI is nothing more than a mathematical ratio that provides a standardized starting place. The old height/weight charts did the same thing. Start with either BMI or a height/weight chart, but don't end there. Again -- it's mathematical, and it provides a sort of average of what might be an appropriate weight range. It's based solely on height and weight, with no allowance made for frame size, or muscle/fat ratio, or even gender in most cases. There are actually a couple of online BMI calculators that do offer different versions for men and women, but all the other issues still apply.
And actually, there's a whole lot written about those problems all over the internet...
As far as it goes, I like the BMI calculator offered here. It's easy to use, it offers a mathematical calculation to adjust for age, and it has that nifty little "if you're shooting for a particular BMI, here's how to calculate it" function. I like that. ;-) And, since I don't believe that BMI is the best judgement about weights, it's good enough for me.
Posted by fayeroe on October 26, 2006, at 13:31:40
In reply to Yeah, BMI is misleading... » NikkiT2, posted by Racer on October 26, 2006, at 13:22:57
> > >>there is one new opinion that the BMI isn't as important as it was once thought to be, but i've not seen anyone else jump on that guy's bandwagon.
> >
> > The UK is strarting to follow the "BMI isn't important" idea.. My GP's no longer use it, and neither does my pain consultant
> >
> > Nikki
>
> There's actually an awful lot on the internet saying that BMI is misleading if you use it as anything other than a convenient starting point. Athletes will have a much higher BMI than an average person, for instance, and yet they'll hardly be "overweight."
>
> The BMI is nothing more than a mathematical ratio that provides a standardized starting place. The old height/weight charts did the same thing. Start with either BMI or a height/weight chart, but don't end there. Again -- it's mathematical, and it provides a sort of average of what might be an appropriate weight range. It's based solely on height and weight, with no allowance made for frame size, or muscle/fat ratio, or even gender in most cases. There are actually a couple of online BMI calculators that do offer different versions for men and women, but all the other issues still apply.
>
> And actually, there's a whole lot written about those problems all over the internet...
>
> As far as it goes, I like the BMI calculator offered here. It's easy to use, it offers a mathematical calculation to adjust for age, and it has that nifty little "if you're shooting for a particular BMI, here's how to calculate it" function. I like that. ;-) And, since I don't believe that BMI is the best judgement about weights, it's good enough for me.
how my jeans fit works for me........
Posted by fayeroe on October 27, 2006, at 12:03:30
In reply to Re: Yeah, BMI is misleading... » Racer, posted by fayeroe on October 26, 2006, at 13:31:40
> >>there is one new opinion that the BMI isn't as important as it was once thought to be, but i've not seen anyone else jump on that guy's bandwagon.
This is the end of the thread.
Psycho-Babble Administration | Extras | FAQ
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.org
Script revised: February 4, 2008
URL: http://www.dr-bob.org/cgi-bin/pb/mget.pl
Copyright 2006-17 Robert Hsiung.
Owned and operated by Dr. Bob LLC and not the University of Chicago.