Friday Weird Science: A load of S***

Feb 15 2013 Published by under Friday Weird Science, Uncategorized

Today's Friday Weird Science is inspired by Kate Clancy, or rather, Kate Clancy's offspring. Said offspring had the recent misfortune to receive a gift in her shoe. A rather smelly gift. Yup, one of her preschool friends pooped in her shoe.

Nothing like a poop in your shoe to show eternal friendship I guess. Luckily Kate's offspring took it in good part. I figure, that's something so odd you kind of HAVE to laugh it off.

But the story, and other such stories, got me thinking. Poop. We don't talk about it much. Well, ok, some of us do, but usually in terms of things of whether or not we're constipated or have diarrhea, depending on our stress levels and whether a norovirus is going around. But in a normal healthy often do we poop? big is it? I mean, someone must have investigated this question, I have to assume that modern toilets have the latest in ergonomic poop volume disposal design. But who has?

Well, I found one group. And they not only took heroic measures to gather, dry, and weigh poop, they also looked at both high and low fiber diets! We all know that high fiber diets are supposed to...well make things move along, shall we say. But the effect on volume! Oh my.

Kelsay et al. "Effect of fiber from fruits and vegetables on metabolic responses of human subjects: fiber intakes, fecal excretions, and apparent digestibilities." American Journal of Clinical Nutrition, 1981.

The real purpose of this study was actually to look at the digestability of different types of fiber. But what they also ended up looking at was the volume of poop. A LOT of poop.

They had 12 men. 6 were maintained on a high fiber diet (lots of fruits and veggies), while 6 were maintained on low fiber (fruit and veggie juice instead). Over the last 7 days (hey, at least it wasn't all 26) the intrepid researchers bravely weighed every scrap of excrement, and then put them in a BLENDER (um...EW) and freeze-dried them for analysis. Because people go to some pretty extreme lengths for science.

But at least they got significant results! Significantly LARGE results!

You can see that the average poo size for the low fiber diet was 23 grams. Considering that one gram is about the size of a normal bic pen cap:

This means that low fiber people poop on average 23 pen caps worth of poo per day. But the HIGH fiber groups was more than double the output, at 51 grams. 51 pen caps!! That's like a double handful at LEAST. A double handful of pen caps. Just...just stick with the pen cap image, ok?

Of course, these were pretty extreme low and high fiber diets, so most of us probably fall somewhere in the middle, dumping about 35 grams of poop per day (on average).

They talk a bit about digestibility, but it's the poop volume I was after. But it makes me wonder, does this still hold true? What about women? And then there's the other question: DO most of us go every day? Why not every other day? Every three days? What's the average there? You'd think that with pooping being such a very common occurrence we'd know more about it. We clearly need more scientists, brave and willing to handle some poop...for SCIENCE.

Kelsay JL, Goering HK, Behall KM, & Prather ES (1981). Effect of fiber from fruits and vegetables on metabolic responses of human subjects: fiber intakes, fecal excretions, and apparent digestibilities. The American journal of clinical nutrition, 34 (9), 1849-52 PMID: 6269418

3 responses so far

  • Dani Sed says:

    This won't answer any of your questions on volume, but if you're interested in doing a whole poop series, you should write about this article, if only for it's amazing, amazing title. Also, you know, open source journal! Neglected tropical diseases!

  • I wonder how much that blender will fetch on ebay...

  • boba says:

    One other thing you need to control for - water intake. That poo has a great deal of water in it and how much water is in that excrement. Moreover, how much of that fiber is water soluble and so passes through the colon membrane.
    If you want to poo everyday, but don't want a high fiber diet, I recommend Mountain House freeze-dried foods. When hiking, I rely on them for my evening repast. (the morning intake being a not so fiber rich cup of tea with lots of sugar and lunch being jerky, occasionally with peanut butter.) Nevertheless, once vertical in the morning, the expulsion is mandatory. (And one must dig a hole, 6 to 12 inches deep and pack out the paper!) While the exercise obviously contributes (8-12 hour days walking of varied terrain) I swear Mt House has magnesium supplements. Every morning ,within a minute of standing. Cold, Rain, or Snow: Too bad. Dig Hole. Squat.
    Oh, and never use the blender in the lab to make a smoothie.

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