It works like this. You lie down on a bed in the back room of the cardiology unit, next to a huge cylinder. The cylinder is transparent, and inside of it is a bellows which rises up and down; it looks like part of the set from one of the old Mike Hammer Frankenstein films: Frankenstein Must Die(t)!, possibly, or Death to Adipose Cells!.

Next they hook you up to this device by a long plastic hose. Your nostrils are clipped shut, and a nozzle is inserted into your mouth. Then you breathe. In and out. As you breathe, the bellows expands and contracts. This is pure oxygen you’re breathing in now, folks, 100%. I’ve done it before, when very bad asthma attacks kept my lungs from doing their job. Pure oxygen is dry stuff, and after fifteen minutes I had a really bad case of cotton mouth.

Now, somehow this Hammer device measures the oxygen that you breathe out, and calculates the percentage of oxygen that your lungs absorb. And somehow, this number will let the machine determine how many calories per day your body burns in a resting state. The trainer explained this to me and I found myself thinking that it makes a great deal of sense; in my college days, I took at least one course in human physiology, which included a section on energy production. Oxygen is part of the process by which your body converts fuel to energy. Or something. Anyway, in my own case, if I were to spend the day in bed, not moving a muscle, barely even breathing, my body would still burn about 2,000 calories per day just to keep essential functions such as digestion and neural activity going (though I suppose there are some who would claim that if all my neuronic processes stopped, no one would notice the difference; to them I say, "Very funny, Mom").

I know you’re thoroughly fascinated by this already, but now here comes the really interesting part. During the two years that I was out of the Healthy Weight program, I managed to gain about 30 pounds (I’m not ashamed to mention that, especially since more than half of that is gone again). The trainer and I decided to conduct a little mental exercise to see how many calories, total, I had consumed during that time; since a pound of fat is about 3,500 calories, we worked out that I had managed to consume something like 105,000 calories above my daily maintenance level. Or, an average of only 14 calories per day above my basal metabolic rate.

Fourteen calories. That’s something like a single potato chip. Can you imagine that a single extra potato chip consumed every single day for two years can add up to thirty pounds in weight gain? Is the human body incredible, or what?

Of course, your body doesn’t burn just that basal metabolic rate each day. After all, your days are filled with walking around, working, typing, possibly even exercise, which bring up your daily burn by a few hundred calories. And if you work out, you can burn even more. The whole point of this program I’m in is to create a deficit between the number of calories that you burn in a day and the number of calories that you take in. Now if you lead a really sedentary lifestyle, like the one I’m trying hard to shed, you can’t afford to eat a whole lot; but if you lead a very active lifestyle, it’s easier to create that deficit, and lose weight.

And, of course, as you exercise more, increasing your lungs’ efficiency and your heart’s strength, your basal metabolic rate will actually go down. Especially if you lose a lot of weight: just carrying your bulk around gives your legs a good workout every time you walk to the bathroom.

So I got my Basal Metabolic Rate read. It was an enlightening experience, and I learned quite a bit. And because God only knows what kind of germs I breathed out during the process, they even let me keep the hose that I was connected to the cylinder with. It’s sitting in a big plastic bag in my car even as I write this, awaiting a time when I will come up with a practical use for a six-foot translucent hose with a mouthpiece on one end. Suggestions are more than welcome.