Limits of using BMI

WillBrink · 02-28-2008, 08:04 AM

For those of you who don't fit the BMI charts (I would be considered obese FYI) a study that confirms much of what I have always said about BMI:

Int J Obes (Lond). 2008 Feb 19

Accuracy of body mass index in diagnosing obesity in the adult general population.

Romero-Corral A, Somers VK, Sierra-Johnson J, Thomas RJ, Collazo-Clavell ML, Korinek J, Allison TG, Batsis JA, Sert-Kuniyoshi FH, Lopez-Jimenez F.

1Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, MN, USA.

Background: Body mass index (BMI) is the most widely used measure to diagnose obesity. However, the accuracy of BMI in detecting excess body adiposity in the adult general population is largely unknown.Methods: A cross-sectional design of 13 601 subjects (age 20-79.9 years; 49% men) from the Third National Health and Nutrition Examination Survey. Bioelectrical impedance analysis was used to estimate body fat percent (BF%).

We assessed the diagnostic performance of BMI using the World Health Organization reference standard for obesity of BF%>25% in men and>35% in women. We tested the correlation between BMI and both BF% and lean mass by sex and age groups adjusted for race.

Results: BMI-defined obesity (>/=30 kg m(-2)) was present in 19.1% of men and 24.7% of women, while BF%-defined obesity was present in 43.9% of men and 52.3% of women. A BMI>/=30 had a high specificity (men=95%, 95% confidence interval (CI), 94-96 and women=99%, 95% CI, 98-100), but a poor sensitivity (men=36%, 95% CI, 35-37 and women=49%, 95% CI, 48-50) to detect BF%-defined obesity. The diagnostic performance of BMI diminished as age increased. In men, BMI had a better correlation with lean mass than with BF%, while in women BMI correlated better with BF% than with lean mass. However, in the intermediate range of BMI (25-29.9 kg m(-2)), BMI failed to discriminate between BF% and lean mass in both sexes.

Conclusions: The accuracy of BMI in diagnosing obesity is limited, particularly for individuals in the intermediate BMI ranges, in men and in the elderly. A BMI cutoff of>/=30 kg m(-2) has good specificity but misses more than half of people with excess fat. These results may help to explain the unexpected better survival in overweight/mild obese patients.

fufu · 02-28-2008, 09:34 AM

Yeah, BMI can be a load of shit. With athletic people and weight lifters it is useless.

danzik17 · 02-28-2008, 03:57 PM

If I remember correctly (how the hell do I remember this) isn't P-funk considered obese according to his BMI?

Hoglander · 02-28-2008, 04:09 PM

I'm at "31.6" hahaha good times : )

Calculate your BMI - Standard BMI Calculator

tomuchgear · 03-01-2008, 10:35 PM

bmi is good for small children who's parents dont know what freakin diet is besides mcdonalds, and any one who goes on the biggest loser.

**Gazhole** · 03-02-2008, 05:08 AM

Quote:

Originally Posted by danzik17

If I remember correctly (how the hell do I remember this) isn't P-funk considered obese according to his BMI?

No, i remember the same thing. He was having health insurance troubles because the company saw his BMI and assumed he was a fatty.

BMI sucks.

**P-funk** · 03-02-2008, 11:30 AM

The worst part about BMI is that this is what medical institutions and insurance companies use to determine if you are healthy or not.

Believe it or not, I pay a higher health insurance amount because I am listed as obese on the BMI chart. (5'5", 187lbs).

Witchblade · 03-02-2008, 02:28 PM

It's sad people even need a study to realize this.

Yanick · 03-04-2008, 08:50 PM

Damn and i've been kicking my own ass in this other thread about BMI

http://www.ironmagazineforums.com/op...y-fitness.html (Determine your body fitness)

It is useless for athletes. And it has its limits, but with the general population it is a useful tool when assessing a patient's overall health. It is not to be used blindly, but as part of a series of tests to assess a patient's risk factors for the development of pathologies.

Unfortunately people like Patrick have to pay the price (as i probably will as well because i've been obese according to BMI since i was 16 years old). Pat you never went for a physical or anything? A licensed physician must assess you and diagnose you to be considered obese, a BMI number is just a number if it is not taken in context with other factors.

**P-funk** · 03-04-2008, 10:32 PM

No, i didn't go to get a physical. I was just putting in the info on my health insurance form (didn't even think about it) and I put in height and weight and then they just send you a letter telling you what you have to pay and that I had to pay more because I was a fat ass......this world is so harsh! I will probably have to get 2 plane seats on thursday to fit my fat ass on the flight.

Yanick · 03-05-2008, 08:30 AM

Sorry to hear about that fatty. Where the fuck are you flying off to?

PreMier · 03-05-2008, 10:45 AM

im 28.2

BMI Categories:

Underweight = <18.5
Normal weight = 18.5-24.9
Overweight = 25-29.9
Obesity = BMI of 30 or greater

02-28-2008, 08:04 AM	#1
WillBrink Registered User Join Date: Mar 2005 Location: MA Posts: 444	Limits of using BMI BODYBUILDING SUPPLEMENTS High Quality Supplements For Bodybuilders and Athletes. www.ironmaglabs.com For those of you who don't fit the BMI charts (I would be considered obese FYI) a study that confirms much of what I have always said about BMI: Int J Obes (Lond). 2008 Feb 19 Accuracy of body mass index in diagnosing obesity in the adult general population. Romero-Corral A, Somers VK, Sierra-Johnson J, Thomas RJ, Collazo-Clavell ML, Korinek J, Allison TG, Batsis JA, Sert-Kuniyoshi FH, Lopez-Jimenez F. 1Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, MN, USA. Background: Body mass index (BMI) is the most widely used measure to diagnose obesity. However, the accuracy of BMI in detecting excess body adiposity in the adult general population is largely unknown.Methods: A cross-sectional design of 13 601 subjects (age 20-79.9 years; 49% men) from the Third National Health and Nutrition Examination Survey. Bioelectrical impedance analysis was used to estimate body fat percent (BF%). We assessed the diagnostic performance of BMI using the World Health Organization reference standard for obesity of BF%>25% in men and>35% in women. We tested the correlation between BMI and both BF% and lean mass by sex and age groups adjusted for race. Results: BMI-defined obesity (>/=30 kg m(-2)) was present in 19.1% of men and 24.7% of women, while BF%-defined obesity was present in 43.9% of men and 52.3% of women. A BMI>/=30 had a high specificity (men=95%, 95% confidence interval (CI), 94-96 and women=99%, 95% CI, 98-100), but a poor sensitivity (men=36%, 95% CI, 35-37 and women=49%, 95% CI, 48-50) to detect BF%-defined obesity. The diagnostic performance of BMI diminished as age increased. In men, BMI had a better correlation with lean mass than with BF%, while in women BMI correlated better with BF% than with lean mass. However, in the intermediate range of BMI (25-29.9 kg m(-2)), BMI failed to discriminate between BF% and lean mass in both sexes. Conclusions: The accuracy of BMI in diagnosing obesity is limited, particularly for individuals in the intermediate BMI ranges, in men and in the elderly. A BMI cutoff of>/=30 kg m(-2) has good specificity but misses more than half of people with excess fat. These results may help to explain the unexpected better survival in overweight/mild obese patients.
	Will Brink @ WWW.BRINKZONE.COM

02-28-2008, 09:34 AM	#2
fufu fiendish thingy Elite Member Join Date: Nov 2005 Location: Massachusetts Posts: 15,480 Photos: 3	Yeah, BMI can be a load of shit. With athletic people and weight lifters it is useless.
	fufu's 1337 Journal Your diet will set you free.

02-28-2008, 03:57 PM	#3
danzik17 Gender: MALE Elite Member Join Date: Oct 2005 Location: New York Posts: 1,489 Blog Entries: 5	If I remember correctly (how the hell do I remember this) isn't P-funk considered obese according to his BMI?
	Ron Paul 2008 Journal: Boom goes the dynamite

03-02-2008, 11:30 AM	#7
P-funk Patrick Super Moderator Join Date: Dec 2002 Location: AZ Posts: 30,136	The worst part about BMI is that this is what medical institutions and insurance companies use to determine if you are healthy or not. Believe it or not, I pay a higher health insurance amount because I am listed as obese on the BMI chart. (5'5", 187lbs).
	http://pwtraining.blogspot.com/.....come and see what is on my mind! http://ivonneberkowitz.blogspot.com/....check out Ivonne's new blog! Optimum Sports Performance "In the beginners mind there are many possibilities, in the experts there are few." -Buddha's Little Instruction Book

03-02-2008, 02:28 PM	#8
Witchblade Succinct Elite Member Join Date: Jul 2006 Location: Holland Posts: 3,942 Photos: 2	It's sad people even need a study to realize this.
	My Journal My Linkdump [LSFW] IM Official FAQ [WORK IN PROGRESS]

02-28-2008, 04:09 PM	#4
Hoglander Cleaner Join Date: Jun 2007 Location: Washington Posts: 914 Blog Entries: 1 Photos: 10	I'm at "31.6" hahaha good times : ) Calculate your BMI - Standard BMI Calculator

03-01-2008, 10:35 PM	#5
tomuchgear gettin there Elite Member Join Date: Jan 2008 Location: ohio Posts: 1,063 Photos: 2	bmi is good for small children who's parents dont know what freakin diet is besides mcdonalds, and any one who goes on the biggest loser.

03-04-2008, 08:50 PM	#9
Yanick Amor Fati Join Date: Jul 2002 Posts: 3,767	Damn and i've been kicking my own ass in this other thread about BMI http://www.ironmagazineforums.com/op...y-fitness.html (Determine your body fitness) It is useless for athletes. And it has its limits, but with the general population it is a useful tool when assessing a patient's overall health. It is not to be used blindly, but as part of a series of tests to assess a patient's risk factors for the development of pathologies. Unfortunately people like Patrick have to pay the price (as i probably will as well because i've been obese according to BMI since i was 16 years old). Pat you never went for a physical or anything? A licensed physician must assess you and diagnose you to be considered obese, a BMI number is just a number if it is not taken in context with other factors.
Yanick Amor Fati Join Date: Jul 2002 Posts: 3,767	"...we have to remember that training is a complicated dance of stimuli and response. Our goal is to understand how to manipulate the stimuli in order to evoke the responses we desire." -Nathan J. Polenchek

03-04-2008, 10:32 PM	#10
P-funk Patrick Super Moderator Join Date: Dec 2002 Location: AZ Posts: 30,136	No, i didn't go to get a physical. I was just putting in the info on my health insurance form (didn't even think about it) and I put in height and weight and then they just send you a letter telling you what you have to pay and that I had to pay more because I was a fat ass......this world is so harsh! I will probably have to get 2 plane seats on thursday to fit my fat ass on the flight.
	http://pwtraining.blogspot.com/.....come and see what is on my mind! http://ivonneberkowitz.blogspot.com/....check out Ivonne's new blog! Optimum Sports Performance "In the beginners mind there are many possibilities, in the experts there are few." -Buddha's Little Instruction Book

03-05-2008, 08:30 AM	#11
Yanick Amor Fati Join Date: Jul 2002 Posts: 3,767	Sorry to hear about that fatty. Where the fuck are you flying off to?
Yanick Amor Fati Join Date: Jul 2002 Posts: 3,767	"...we have to remember that training is a complicated dance of stimuli and response. Our goal is to understand how to manipulate the stimuli in order to evoke the responses we desire." -Nathan J. Polenchek

03-05-2008, 10:45 AM	#12
PreMier happy sumo Elite Member Join Date: Sep 2003 Posts: 20,999 Photos: 1	im 28.2 BMI Categories: Underweight = <18.5 Normal weight = 18.5-24.9 Overweight = 25-29.9 Obesity = BMI of 30 or greater
	P-side Inc. "the post-workout high is more profound than any drug-induced rush imaginable." -Dante B.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode