Tuesday, 30 April 2013

Metabolic flexibility - do you have it?

I'm not quite sure what the picture below means (I need to do a spot of reading!).
Metabolic flexibility "bowl" and "Adaptability envelope"
While replying to Kade Storm this morning, it suddenly occurred to me that the Eskimos have an unusual ability. RER (a.k.a. RQ) normally varies from 0.7 (100% fat-burning) to 1.0 (100% carb-burning aerobically) to >1.0 (100% carb-burning, some anaerobically). Eskimos manage to get an RER of 0.600 *Mind blown.*

One theory that comes to mind is BAT. As Eskimos live in a very cold environment, it's possible that this has resulted in them having a large amount of BAT. BAT is very metabolically-active and turns ATP into heat via UCPs.

Nowadays, first-world people don't live in a cold environment (unless they're old and/or poor), so we don't have much BAT after infancy. Naturally-skinny people may be that way due to having more BAT. They seem to be able to eat whatever and as much as they want without getting fat. I'd like to scratch their eyes out! ;-)


Unknown said...

Ah. Bloody hell! Now do I have to get a restraining order against you on account of keeping my eyes?

True, many of us do get away with a lot of crap without much by way of substantial 'weight gain'. However, I do think that other negative health issues arise from poor dietary choices. We could be lean as hell and still have poor glucose control, high cortisol, a screwed up HPA axis and much more. You get the idea.

Nigel Kinbrum said...

I was quoting my ex-G/F. Women seem to want to scratch out other women's eyes for various reasons (like wearing the same top). Your eyes are safe with me (whatever that means).

I agree. Being skinny doesn't guarantee being healthy.

I'm still trying to figure out what a RER of 0.600 means, in terms of fuel usage.

Bill said...

0.6 FTW! that's pretty impressive.

Nigel Kinbrum said...

Off the top of my head, an RER of 0.600 means that 133% of the body's energy is coming from fat.

As contestants on "The Apprentice" are always "giving 110%", I'm still somewhat confused!

Bill said...

Interesting, indeed - weird things start to happen when ketosis is challenged by a high protein diet.

Nigel Kinbrum said...

If it was possible for the human body to oxidise pure hydrogen into water for energy, RER would be 0, as no CO2 would be produced.

Therefore, RER <0.7 suggests that some hydrogen from "somewhere" is being oxidised for energy. Where this hydrogen comes from, I have no idea!