Nutritional value of dust?

To preface my odd question – there used to be a show on BBCA that we would watch called Little Britain. It is a sketch comedy show. One of the recurrent sketches is about a Weight Watcher’s style support group. In one of the sketches, the leader of the group suggests that everyone should eat dust, as it has no calories. One night at dinner, my daughter brought up this sketch and asked what my honest opinion was – how many calories in dust. Yeh, we talk about unusual things at our dinner table.

Now, IIRC dust is made up of somewhere in the neighborhood of 90% discarded skin cells. While skin wouldn’t be a whole protein, it would be mostly protein, so I am thinking around 8-9 calories per gram or 230 calories per ounce. (28 grams per oz, right?) Holy crap, dust is heavy on the calories! :eek:

So, Dopers – what’s the scoop? How many calories in an ounce of dust?

First, your numbers are all wrong.

Protein is 4 calories per gram. Skin cells are not 90% of dust. I find varying results from googling, but 70-80% seems to be the norm.

And you’re forgetting the other components of dust.

I’m not sure how quickly the proteins degrade in loose skin cells, but you’d probably find more nutrition in the dust mites, fungi or bacteria than in the skin. Know what dust mites eat? Skin cells. Thus subtracting some of them from the equation.

Unfortunately, where there are dust mites there are dust mites droppings, and their droppings can trigger allergies in some people. The fiber and pollen can also be troublesome.

People always seem to forget that there are two sides to every equation. Even if you could choke down a gram of dust - which would be a large volume - the number of calories would be the least of your worries.

This is why I came to the SDMB. For some reason, my quick math was using 9 calories per gram (thinking of fat instead of protein). This isn’t about whether or not anyone would ever actually eat an oz of dust, just how many calories (even approximate values would be nice) one would be consuming if one did so. I am thinking the dust mites and their droppings would be mostly protein, though. Assuming this – and that would still have the protein content of dust around 90% of the total – we’re talking 100 calories or thereabouts.

Funny enough, when I typed the OP, I thought that the 200-calorie mark was a bit high. I remember saying around 100 calories when we discussed this at dinner that night. Someone step up to the plate and fix my numbers, wouldja? This topic came up again last night and now we are genuinely curious.