The Answer : So imagine my surprise when this little theoretical paper (note the journal title) showed up on my Pubcrawler last year (1). Titled, “A limit on the energy transfer rate from the human fat store in hypophagia”, it examined (from a somewhat simplified and theoretical way) exactly the question I gave above: what is the maximum rate at which the body can derive energy from fat stores to cover a diet induced deficit while sparing lean body mass. It’s a nasty little paper, filled primarily with equations, explanations of those equations and some more equations to boot. Headache inducing to be sure.
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I’ll spare you the details. Based on a somewhat simplified analysis of what data exists (including the seminal Minnesota semi-starvation experiment), they conclude that the maximal rate at which fat stores can provide energy to the body is 290 +- 25 kj/kg which is approximately 31 kcal/lb of fat per day.
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So, if you are carrying a mere 10 lbs. of fat, you can sustain a 310 cal/day deficit.
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20 lbs. = 620 calories.
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30 lbs. = 930 calories
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2 comments:
Very interesting. I Love formulas. Let me see, E=MC2. Is that energy=Mass times the speed of light squared. That means that the bigger the mass, the more energy you can get out of it. I think if we run at the speed of light, we will have infinate power. Ok i will just not eat and see what happens. :)
I am from Florida originally and don't carry an accent. I can fake a pretty good one though. You should hear the bubba's I work with though. It would kill you. Have a great day, Greg
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