Some facts about calories

[Malaspina]

If you've read Vapor's thread on fat loss, you certainly know that checking your calories intake is fundamental. (btw, if you're interested in getting leaner and you haven't read it, do it now!).

But what is a calorie? how does this stuff work? here are some facts you may find interesting:

- originally, a calorie was a unit of energy, mostly heat. It's defined as the amount of heat required to raise the temperature of a 1 g of water by 1°C. Hence, a kilocalorie, or 1000 calories, would be the heat required to raise the temperature of 1 Kg of water by 1°C;

- the kcal you read labeled on packages is that same thing; but this time it's not heat, it's some other form of energy that your body gets by digesting food;

- what this energy actually IS is a damn hard thing to figure out, but you can imagine it as the energy content of fuel: by digestion, you're kind of refining crude oil into gas; some of the oil's original energy is lost in the process;

- when the fuel gets pumped to where it's needed, some of it gets lost;

- it's then stored in various ways (NOT ONLY BODY FAT): some of it always ready for use, some of it is stored away for later usage;

- when it's finally "burnt" by cells, the process is far from efficent; in fact, it's much less efficent than your car's engine. When muscles turn "fuel" into motion, the efficiency is around 15%, which sucks.

THE GOOD NEWS: all this mess is taken care of by the people who write the labels. Experiments were made to determine how much the human body absorbs, so what you read on the labels is a good estimate of what your body is gonna get.

THE BAD NEWS: as making these estimates is a long a costly process, most of them are made by finding out the protein, fat, carbohydrates etc. content of the food, then using some premade tables to determine the caloric intake of each component. What this means is that estimates are not THAT precise, because percentages are difficult to control during production plus experimental error etc. etc. And if you wanna think ill of food companies.."lighter" food is better marketed than fat sticks.

SOME MORE GOOD NEWS: when you go the gym, most of the equipment will tell ya how many kcals you've just burnt. They are so kind they take into account the low efficency of your muscles, so that number really is the amount of calories that you have burnt. This estimate is quite good 'cause differencies in muscle efficiency from guy to guy are not that wide, PLUS machine makers don't sale more stuff 'cause they tell ya you've burnt some 30 cals more than real, do they?

so that's about everything about cals. if you've got questions, I suggest you check wikipedia 'cause I'm not gonna be around for a while (holydays you know).