D
DZ
Guest
JMW wrote:
> DZ wrote:
>>JMW wrote:
>>> DZ wrote:
>>>>You're right. I mistook REE/FFM as to mean REE/LBM. Also, the
>>>>correlation in the graph doesn't seem to hold within genders, so I'm
>>>>no longer sure what to make of that graph.
>>>
>>> No, it makes perfect sense. Women have a higher REE/FFM because a
>>> much higher percentage of their FFM is organs, as opposed to skeletal
>>> muscle. The men will still have a higher total REE.
>>
>>Your explanation is consistent with the graph but it doesn't rule out
>>a gender-specific relation. In that case we have two round circles of
>>dots within sexes (zero correlation) and the overall correlation can
>>be spurious due to some other differences between the sexes (I'd
>>rather see ellipses formed by the dots of the same color).
>
> Well, the following article might develop my theory a bit further,
> since it examines gender differences as well as racial differences:
> http://www.ajcn.org/cgi/content/abstract/83/5/1062
>
> I assume it has some conclusions regarding both dichotomies
....
There isn't much more on that than what's in the abstract. Sex and
race correlate with REE and when the ratio of muscle mass to the mass
of highly metabolically active organs is taken into account, the
difference in REE between the groups becomes no longer significant. I
think the reality of such research is that there is always a
confounding variable unaccounted for. We should take care of the
obvious ones and hope that what remains has a small effect. That's why
I'd rather see a relation within homogeneous groups. However, I don't
disagree with you that when REE is measured for all metabolically
active organs, a most reasonable explanation of the decrease in REE
with the additional muscle mass is a change in proportion of that mass
to the total (so the part that consists of more metabolically active
organs becomes smaller in proportion).
> DZ wrote:
>>JMW wrote:
>>> DZ wrote:
>>>>You're right. I mistook REE/FFM as to mean REE/LBM. Also, the
>>>>correlation in the graph doesn't seem to hold within genders, so I'm
>>>>no longer sure what to make of that graph.
>>>
>>> No, it makes perfect sense. Women have a higher REE/FFM because a
>>> much higher percentage of their FFM is organs, as opposed to skeletal
>>> muscle. The men will still have a higher total REE.
>>
>>Your explanation is consistent with the graph but it doesn't rule out
>>a gender-specific relation. In that case we have two round circles of
>>dots within sexes (zero correlation) and the overall correlation can
>>be spurious due to some other differences between the sexes (I'd
>>rather see ellipses formed by the dots of the same color).
>
> Well, the following article might develop my theory a bit further,
> since it examines gender differences as well as racial differences:
> http://www.ajcn.org/cgi/content/abstract/83/5/1062
>
> I assume it has some conclusions regarding both dichotomies
....
There isn't much more on that than what's in the abstract. Sex and
race correlate with REE and when the ratio of muscle mass to the mass
of highly metabolically active organs is taken into account, the
difference in REE between the groups becomes no longer significant. I
think the reality of such research is that there is always a
confounding variable unaccounted for. We should take care of the
obvious ones and hope that what remains has a small effect. That's why
I'd rather see a relation within homogeneous groups. However, I don't
disagree with you that when REE is measured for all metabolically
active organs, a most reasonable explanation of the decrease in REE
with the additional muscle mass is a change in proportion of that mass
to the total (so the part that consists of more metabolically active
organs becomes smaller in proportion).