Re: BMI (Body Mass Index)

Logician <sales@logicians.com> writes:

> On Aug 15, 4:57 pm, The Master <tar...@nospam.sdf.lonestar.org.nospam>
> wrote:
>> On Fri, 15 Aug 2008, Logician wrote:
>> > Can anyone explain this apparent contradiction between the BMI and
>> > fitness.
>>
>> Body MASS Index means just that, how much mass you have. Muscle and bones
>> have mass, just like fat. So yes, you will have a larger mass, and thus
>> give you a higher weight. Think of it as the "brain dead fitness
>> measure".
>
> So is overweight healthy when the excess weight is from muscle weight?

To a large extent that is a question that hasn't really even been asked
by the medical community. There is one study that I know of that
signaled good news for people that are large and fit. The study was by
Dr Xuemei Sui (University of South Carolina, Columbia) and you can find
a summary here:

http://www.medscape.com/viewarticle/566963

Just in case you can see the article, here's an except.

The study tracked a cohort of 2603 adults aged 60 or over for a
mean of 12 years, during which time 450 people died. Adjusted
death rates were lowest for people with the lowest body-mass
index (BMI), lowest waist circumference, or in the highest
quintile for fitness level — this last that held true even in
severely obese subjects, who were much less likely to die if
their fitness levels were higher. When fitness was factored into
the waist circumference analysis and vice versa, fitness
predicted mortality risk regardless of smoking, baseline health,
BMI, waist circumference, or percent body fat, whereas waist
circumference was no longer significantly associated with
increased mortality after fitness was considered.

Personally, I think that it is dangerous to read too much into this
particular study, and I say that as a person that is responding from
misc.fitness.weights and who is definitely interested in getting larger
and more muscular.

If your primary interest is longevity a low body mass index is probably
the best strategy.

Jason

Jason Earl wrote:
> Logician <sales@logicians.com> writes:
>
>> On Aug 15, 4:57 pm, The Master <tar...@nospam.sdf.lonestar.org.nospam>
>> wrote:
>>> On Fri, 15 Aug 2008, Logician wrote:
>>>> Can anyone explain this apparent contradiction between the BMI and
>>>> fitness.
>>> Body MASS Index means just that, how much mass you have. Muscle and bones
>>> have mass, just like fat. So yes, you will have a larger mass, and thus
>>> give you a higher weight. Think of it as the "brain dead fitness
>>> measure".
>> So is overweight healthy when the excess weight is from muscle weight?
>
> To a large extent that is a question that hasn't really even been asked
> by the medical community. There is one study that I know of that
> signaled good news for people that are large and fit. The study was by
> Dr Xuemei Sui (University of South Carolina, Columbia) and you can find
> a summary here:
>
> http://www.medscape.com/viewarticle/566963
>
> Just in case you can see the article, here's an except.
>
> The study tracked a cohort of 2603 adults aged 60 or over for a
> mean of 12 years, during which time 450 people died. Adjusted
> death rates were lowest for people with the lowest body-mass
> index (BMI), lowest waist circumference, or in the highest
> quintile for fitness level — this last that held true even in
> severely obese subjects, who were much less likely to die if
> their fitness levels were higher. When fitness was factored into
> the waist circumference analysis and vice versa, fitness
> predicted mortality risk regardless of smoking, baseline health,
> BMI, waist circumference, or percent body fat, whereas waist
> circumference was no longer significantly associated with
> increased mortality after fitness was considered.
>
> Personally, I think that it is dangerous to read too much into this
> particular study, and I say that as a person that is responding from
> misc.fitness.weights and who is definitely interested in getting larger
> and more muscular.
>
> If your primary interest is longevity a low body mass index is probably
> the best strategy.
>
> Jason
And imo, BMI is only of relevance at the population level, not at the
individual level for many reasons including those stated above.

Bob

Bob Volkmer <mfw@volkmer.biz> writes:

> Jason Earl wrote:
>> Logician <sales@logicians.com> writes:
>>
>>> On Aug 15, 4:57 pm, The Master <tar...@nospam.sdf.lonestar.org.nospam>
>>> wrote:
>>>> On Fri, 15 Aug 2008, Logician wrote:
>>>>> Can anyone explain this apparent contradiction between the BMI and
>>>>> fitness.
>>>> Body MASS Index means just that, how much mass you have. Muscle and bones
>>>> have mass, just like fat. So yes, you will have a larger mass, and thus
>>>> give you a higher weight. Think of it as the "brain dead fitness
>>>> measure".
>>> So is overweight healthy when the excess weight is from muscle weight?
>>
>> To a large extent that is a question that hasn't really even been
>> asked by the medical community. There is one study that I know of
>> that signaled good news for people that are large and fit. The study
>> was by Dr Xuemei Sui (University of South Carolina, Columbia) and you
>> can find a summary here:
>>
>> http://www.medscape.com/viewarticle/566963
>>
>> Just in case you can see the article, here's an except.
>>
>> The study tracked a cohort of 2603 adults aged 60 or over for
>> a mean of 12 years, during which time 450 people
>> died. Adjusted death rates were lowest for people with the
>> lowest body-mass index (BMI), lowest waist circumference, or
>> in the highest quintile for fitness level — this last that
>> held true even in severely obese subjects, who were much less
>> likely to die if their fitness levels were higher. When
>> fitness was factored into the waist circumference analysis
>> and vice versa, fitness predicted mortality risk regardless
>> of smoking, baseline health, BMI, waist circumference, or
>> percent body fat, whereas waist circumference was no longer
>> significantly associated with increased mortality after
>> fitness was considered.
>>
>> Personally, I think that it is dangerous to read too much into this
>> particular study, and I say that as a person that is responding from
>> misc.fitness.weights and who is definitely interested in getting larger
>> and more muscular.
>>
>> If your primary interest is longevity a low body mass index is probably
>> the best strategy.
>>
>> Jason

> And imo, BMI is only of relevance at the population level, not at the
> individual level for many reasons including those stated above.
>
> Bob

I certainly *hope* that BMI is not relevant at the individual level, but
science hasn't really tackled the question of whether there is a price
to pay for being large and muscular. This study shows that an
individual's fitness level is more important than BMI or waist
circumference for this particular population (over 60), but it doesn't
necessarily say being large is as safe as being small.

Being strong (and not just strong for my weight) is important enough to
me that I am willing to risk a higher BMI, but I still consider this to
be a calculated risk.

Right now nearly all of the clinical data on the effects of body weight
on health that we have is expressed in terms of BMI. This is primarily
because BMI is much easier and cheaper to calculate than any sort of
body fat measurement. BMI is also not subject to any sort of
interpretation (caliper body fat measurements definitely are somewhat
subjective). Hopefully some day someone will actually measure the
effects of body weight on a population using something besides BMI, but
so far this hasn't really happened.

Jason