why does a child have a hgher metabolic rate than an old man?

[Guest ingenium]

Err...you might know the answer but I don't.

Why does a child have a hgher metabolic rate than an old man?

 

Thanks

[swansont]

One reason is thermodynamic - smaller objects shed heat more readily, so a higher metabolism is needed in order to maintain body temperature.

[Bluenoise]

Yeah they also don't spend so much time sitting on their ass. Physical activity raises metabolic rate quite a bit. lol

 

They tend to act more enegetically in the various activites they do as well. But yeah body heat obviously has something to do with it.

I guess growth would also effect it as well, since that requires energy.

 

There are multiple factors, generally the more energy you use the higher your metabolism to supply that energy. Alot of people seem to think that metabolims is some magical thing where some people are cursed with a low metabolism and become fat and others are lucky and have a high one and stay thin. While genetics definatley has something to do with it, metabolims is more so an indirect consequence of other genetically determined features than directy predispositioned (strange exceptions apply).

 

It's not like some peoples inherant chemical reations just work faster or more efficient than other, like the general public seems to believe (I'm guessing it makes certain people comfortable to believe that their weight is completely out of their control). However it can be at a greater rate if the body requires more energy.

 

Also between adults percentage muscle mass is another huge factor, but I don't this applies to your particular question. Muscle requires more enegy to maintain.

 

These are also one of the main reasons why excercise makes you feel better and smarter. It excellerates metabolism freeing up more energy for other things. While a lack of physical activity results in feeling lathurgic and depressed etc... Glucose metabolism in the brain is linked to intelligence, even though this is mostly in the context of lack of in certain dissorders, don't be surprised if letting your metabolism drop to low negatively effects this. In healthy individuals this correlation doesn't seem significant however, but low metabolism may make you lazy and less likely to use the intelligence that you got (just a thought, don't quote me on that last one ).

 

*edit* actually it seems heart rate and glucose metabolism can effect certain cognitive tasks in healthy people.

Psychopharmacology (Berl). 2000 Mar;149(1):63-71.

 

Just some food for thought ha ha (forgive the pun)

 

 

Oh don't forget about food!! If you don't eat enough your metabolism will severly drop. You'll feel tired, slow, unmotivated, and pretty bad all around as a consequece as well.

 

Lol sorry went abit of topic but I've actually been thinking about this alot the past few days.