The author of The Hacker’s Diet, John Walker, has generously given me permission to discuss his diet in detail using some quotes, with links back to his site. (Earlier E4T articles on The Hacker’s Diet)

Today I’m reading about The Rubber Bag:

The truth, I suspect, lies somewhere between these extremes. Nonetheless, when it comes to gaining and losing weight, the human body is remarkably akin to a rubber bag. Fad diets and gimmick nutritional plans obscure this simple yet essential fact of weight control: if you eat more calories than you burn, you gain weight; if you eat fewer calories than you burn, you lose weight.

Here’s your body, reduced to a rubber bag.

(snip)The first step is identifying what we want to control. Well, that’s obvious: the goal is control our weight. Our weight is just the contents of the rubber bag.

So, what are the inputs to the system? Again, simple. There’s only one input: how much we eat, measured in calories per day.

What are the outputs from the system? Almost as simple: how much we burn, again measured in calories per day, and what comes out. But since what comes out is for all intents and purposes simply the discarded waste products from processing what’s been eaten and, in any case isn’t subject to control, we can ignore it.

(snip)

Intake, burning, and excretion determine, in large part, how you look, how you feel, and how many years you’ll live. They do this because, through simple arithmetic, they control the contents of the rubber bag. Living, as we do, inside the bag, it’s worth understanding how we’re affected by these processes, then using that understanding to gain control of them.

In The Hacker’s Diet, we’re looking at our bodies as a system that we can to some degree control. And he’s going to help us develop the tools to do that. Tomorrow I’ll be reading about What Goes In.