

Study Suggests Lower Mortality Risk for People Deemed to Be Overweight - credo
http://www.nytimes.com/2013/01/02/health/study-suggests-lower-death-risk-for-the-overweight.html

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tallanvor
BMI was never even meant to be an individual indicator of health. It was an
attempt to classify larger groups. It also uses the same values for men and
women, even though men typically have more muscles than women, raising their
BMI.

Any individual who relies on BMI to decide whether or not they are overweight
is doing it wrong.

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Lost_BiomedE
Agreed. Also, as we age, lower weight is associated with chronic or terminal
illness. I haven't opened up the study, but unless they only looked at healthy
participants, this will be another large confounding variable.

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kleiba
_The report on nearly three million people found that those whose B.M.I.
ranked them as overweight had less risk of dying than people of normal weight.
And while obese people had a greater mortality risk over all, those at the
lowest obesity level (B.M.I. of 30 to 34.9) were not more likely to die than
normal-weight people._

I seriously don't understand this paragraph. Maybe it's because I'm a geek,
but I was always under the impression that the risk of dying was 100% no
matter which group you belong to. I don't understand what the author of the
article is trying to convey here.

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YokoZar
Without having read this study in detail, other possible things tend to muck
up such studies. Suppose you define mortality as "chance of dying within a
year"

1) People who start dying (eg by developing cancer) might take more than a
year, and generally they lose weight when they do so. So even if obesity
caused you to be more likely to get cancer and die, it wouldn't show up in
this sort of data.

2) People who weigh less may be otherwise unhealthy for other reasons -- this
doesn't imply that gaining weight would benefit them. In this sense weight is
an effect of some other cause.

3) We may not be measuring "overweight" correctly -- scale weight is different
from BMI which is different from body fat% which is different from body
density which is different from body volume which is different from other
things closely associated with "weight" (and specifically the stuff you
gain/lose by eating)

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twiceaday
BMI is not a completely accurate indicator of obesity so I'm not at all
surprised they got this mild contradiction. Doubly so because it is an easily-
sellable message.

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jacques_chester
BMI is like KSLOC.

It's the shittiest metric of population health we have ... except for all the
others.

Height and weight is _always_ collected. Blood cholesterol ... yeah, not so
much. So unsurprisingly everything is related back to it.

Anyhow. I'd be amazed if many of we key-hunters-and-karma-gatherers are in
much danger of zooming into the dangerous band at the bottom of the BMI
(modulo EDs).

So, given that most people are not rocking pro-bodybuilder fat-free mass
indexes, the BMI is still better than nothing.

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antihero
Perhaps BMI + body fat + weight able to lift?

