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Support Forum Topic: Yikes!! We (USA) are fatter then we think
Started by: NotThePest
Date: April 27, 2010

Came across this article in MedPageToday.com …     http://www.medpagetoday.com/MeetingCoverage/AACE/19756





By Kristina Fiore, Staff Writer, MedPage Today
Published: April 26, 2010
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner    


BOSTON — The scale of the obesity epidemic may be much worse than currently believed, because the usual measure, body mass index (BMI), is a very insensitive measure of excess body fat, researchers said here.

In a single-center study, 66% of patients classified as obese on the basis of DEXA scanning had BMI values in the nonobese range, according to Eric Braverman, MD, of New York Presbyterian Hospital/Weill Cornell Medical Center.

Among more than 1,000 patients, 56% were obese according to the DEXA results, versus 20% using the standard BMI-based definitions.

Braverman and colleagues presented the findings during a press conference here at the American Association of Clinical Endocrinologists meeting.


Scoffing at BMI as the “baloney mass index,” Braverman said it’s “very likely that obesity is a much bigger epidemic than the 300 million people acknowledged by the World Health Organization.”
Currently 23% of Americans are labeled obese by BMI.
He explained that BMI is just a mathematical equation based solely on height and weight that is too general for diagnosing anything, especially in such an exacting field of clinicians.
“If any endocrinologist would rely on math to calculate thyroid stimulating hormone, for instance, he would be laughed at,” Braverman said.
DEXA scans, on the other hand, provide a direct measurement of body fat percentage. It can spot fat exactly, in every part of the body.
It’s particularly effective, Braverman said, for that part of the population that is known as “thin-but-unfit.” Their condition is known as normal-weight obesity, in which the BMI is low but they have a high percentage of body fat, especially compared with more favorable tissue like muscle.
These patients are at higher risk of dyslipidemia, as well as hypertension among men and cardiovascular disease among women.
The researchers conducted a retrospective analysis of 1,234 patients seen at a private medical practice in the U.S. from 2003 and 2009. All had both BMI measurements and DEXA scans available.
The BMI threshold for obesity was 30; with DEXA, a score of 25% body fat or higher in males and 30% or higher in women marked obesity.
The researchers found that DEXA identified 56% of patients as obese while BMI identified 20% as such.
Some 37% of patients were misclassified with BMI, the researchers indicated.
Among those classified as obese by DEXA, only 34% were classified as obese by BMI.
Also, 5% of patients identified as obese by BMI actually weren’t obese according to DEXA scans.
“These individuals were muscular and large, so they look like they’re high weight but they really had high muscle mass,” Braverman said.
So the researchers concluded that BMI is a highly insensitive measure of obesity prone to under-diagnosis, while direct fat measurements are superior because they show distribution of body fat.
“This means that we may have more health problems, as individuals are delaying treatment because they don’t think they’re obese,” he said. “They think they’re thin and ‘just a little flabby.’”
They called for additional studies to confirm the results and to “determine the true nature of the obesity epidemic.” Further analyses are also needed to identify which patients may be at risk of mislabeling by BMI.
No external funding for the study was reported.
The researchers reported no conflicts of interest.

Primary source: American Association of Clinical Endocrinologists
Source reference:
Braverman E, et al “DEXA more accurately predicts obesity compared to BMI utilizing American Bariatric Society criteria in 1,234 adults in primary care outpatient facility” AACE 2010; Abstract 609.

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5 Responses to “Yikes!! We (USA) are fatter then we think”

  1. Steve says:

    Interesting article … Thank you for posting it!

    The limitations of BMI for individuals is well documented, however this article is interesting in pointing out its limitations for the population overall.

    It is a pity that the study did not look at waist circumference measurements. I believe that the combination of BMI and waist circumference measurement is more accurate. It would have been interesting to see that combination compared to the DEXA body fat scans the article talks about.

    I’m currently researching an article about fructose. It seems that evidence is mounting that fructose could be the cause of the obesity epidemic. Hopefully we’ll have that released in the next couple of days.

    Thanks again for posting this!

    PS: Sorry for the problems with the link. I have fixed it now.

  2. Kellie says:

    Hi NotThePest and Steve,

    I had a laugh at the reference to BMI as the “baloney mass index,” Smiley BMI can be misleading. However, I have found studies that show waist circumference is a good indicator of obesity and health, including blood pressure and heart failure risk.

    I did a review on a study that strongly linked waist size to heart failure risk, even with a healthy BMI.

    http://www.my-health-software.com/view/items/waist-line.html

    It also includes a video showing how to measure your waist accurately. I personally measure my waist circumference by the tightness of my jeans. Smiley

    Thanks, Kellie

  3. NotThePest says:

    Hi Kelly,

    Because uterine fibroids are so prevalent, I’m not sure if the waist circumference will work if you happen to suffer from them, like I did. I formerly had so many fibroids; I had the uterus of a six to seven month pregnant woman.

  4. Kellie says:

    Hi NotthePest,

    Goodness! I know very little about uterine fibroids, I didn’t realise they could protude the stomach similar to a 6-7 month pregnancy. That must have been a very uncomfortable time. Good to hear that you no longer suffer from them.

    Kellie

  5. BellaVega says:

    The BMI is a good test only because it is affordable and easy to do. In fact, someone can do it at home without ever having to see a doctor. If they could make an accurate and affordable test that could be administered quickly and even in non-traditional places like a drug store (like the blood pressure machines), that would be great. It is scary to think that so many Americans are obese. While it’s good to treat obesity with a healthy diet and exercise, I think it’s also important that we tackle the source of what is causing so many people to become obese. -Bella Vega

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