Sunday, January 7, 2007

150 pounds of prevention

I don't like feeling hungry. For me, hunger is not just a sensation, it's an emotion, and I prefer to avoid it. Actually, "avoid" is not the word. I prefer to prevent hunger. I want to get way out in front of it and head it off at the pass. I take pre-emptive steps to make sure it doesn't happen.

On the surface, this makes a certain amount of sense. Why get caught short? You keep the gas tank filled so you don't run out of fuel in the middle of nowhere. You keep money in the checking account so you don't get hit with overdraft fees. Same thing, right?

Wrong. The problem is that filling your belly is not one tiny bit like filling a gas tank. My Subaru's gas tank tops off at 14 gallons and won't take another ounce. The Valero gas pump knows this and obligingly shuts itself off. But the body is a greedy miser, and in a billion years of no-second-chance evolution it has learned to be even more frightened of starvation than I am. Give it too much food, and it instantly, automatically, instinctively scurries around to find a place to put it. Give it even more, and it literally builds on an addition just to make room, with as little hesitation or regret as a classic car collector putting up a new 12-car garage for the latest batch of cherry '68 Camaros he found on eBay.

Exactly how much starvation prevention have I got socked away? Rough calculation: if my surplus 150 pounds are all composed of body fat, and if a pound of body fat is the equivalent of 3,500 calories, I've got 525,000 calories in the bank. A man of my height and age at his ideal weight burns about 2,050 calories a day, according to one of the Web's innumerable online calculators. Half a million calories, on a 2,000 daily allowance, would last 256 days ... or eight and a half months.*

It's January 7th. I shouldn't need to eat again until the last week in August.


*For quantitative geeks only. There are no less than three errors in this calculation, I know. Number one, my 150 extra pounds are surely not all body fat; some is muscle, because schlepping around my weight requires extra muscle. Some is skin, created to cover the extra bulk, and blood, to keep it all irrigated and oxygenated. Second error, it's not right to divide 525,000 by the calorie need of my ideal weight, because I'm not at my ideal weight. If I stopped eating now, I'd start by burning stored fat at a rate based on my current weight, about 4,000 calories a day just to maintain body temperature and basic processes. The smaller I got, the less energy that would take. I think that would take an equation with a logarithm in it, and I'd need to brush up. Besides, and this is another reason not to write the equation, there's a third error: the body is so averse to starvation that it doesn't willingly spend its reserves, no matter how excessive they are. Early in a fast, the metabolic rates slows down in a way not governed by an obvious formula.

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