Energy consumed by body in cold conditions - a working formula, real life

[Q_x]

Something from the book of one of most famous "polar guy".
Marek Kamiński, "Moje Bieguny"
available (partially) on google books.
http://books.google.com/books?id=pGTYldj-gK4C&printsec=frontcover&dq=books+moje+bieguny&source=bl&ots=jB2HYHctkt&sig=8ZLIxLBqLiSAHhjoOLMSBerpmrU&hl=en&ei=hN4lTfPqFMGQswbr28TcAg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBkQ6AEwAQ#v=onepage&q=books moje bieguny&f=false

Page 426 reveals a formula on energy needed by body:

Base energy needed:
66,4 + 13,7*weight (kg) + 6*height (cm) - 6,8*age (years)

Plus body burn due to physical activity (4500 kcal in the example in the book stands for "tremendous exhaustion")

Plus thermal loss:
10% of both of the above summed up

Don't ask me why thermal loss isn't temperature dependent. This guy walked good few thousand miles in polar conditions using the above, so it should work.

Diet is supposed to cover it:
40-50% with fat
12-15% with protein
30-35% with carbohydrates

[zenbitz]

I draw the line at PARPG "nutrition" but at least having a ballpark numbers is useful.

I will probably do something like:

N = some base kcal consumption per hour awake
N/5 = kcal consumed while resting/asleep
Nx3 = kcal consumed under heavy activity (combat, hiking)
X2 per hour for activity outside in extreme cold

For every 100 kcal you are below your "target" per day, your minimum fatigue goes up by 5 pts/day, and your minimum stress goes up 1pt/day.  These points would be recoverable by hitting 110% of target.   Recovery is 2x loss, so 10pts/fatiuge, 2 pts. stress.

See http://wiki.parpg.net/Health_and_Damage for more details about fatigue and stress.