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Americans Could Eat Every American in Less Than Two Decades

This assumes we eat about as much meat as we do now, which is a big assumption when we're talking eating everyone!
Image: Shutterstock

The science research burning up the blog-o-sphere today is a fun one: Martin Nyffeler and Klaus Birkhofer, a pair of European biologists, recently published a paper looking at how much raw tonnage of prey spiders consume every year. It's a fascinating paper—and open access, so you've got no excuse not to read it—that explores the ecological impact of spiders' appetites.

The top-line takeaway? They estimate spiders eat 400-800 million tons of prey annually. As dozens of headlines will tell you today, that's enough to eat all of us humans within a year.


It's a fun way of thinking about something we rarely discuss: the sheer magnitude of life and its processes. If you think about the turnover of energy and biomass inherent to just spiders' diets, and multiply it across the board, you end up with kind of an overwhelming perspective on just how BIG and UNSTOPPABLE life itself is.

(As a wet-blanket counterpoint, it's not surprising that something lower on the food chain would out-consume the biomass of something higher up, since that's just thermodynamics at work. Still, it's a nice way to put humans in their place, since we seem to think we're divorced from nature and all that.)

Anyway, it's a fun paper worth reading. BUT it's also about spiders. We humans tend to care a lot more about humans. So let's tickle our selfish gene: How long would it take us to eat, well, us? Let's do the (very rough) math!

I'm going to focus on America eating itself because a) the numbers I needed were easier to find and b) it seems fitting for 2017.

Average American body weight: I started out by averaging men and women from CDC stats. Our skeletons apparently account for about 15 percent of our body weight, which I subtracted. I lopped off another 5 percent to account for other inedible things like toenails or whatever. This is surely still high for yield but if we're eating each other, I'll assume we're desperate.
180.85 pounds x .80 (edible mass) = 144.68 pounds.


Average American annual meat consumption, per the National Chicken Council. Let's not skew upward for an all-human diet because we still want room for hand salads:
210.8 pounds.

Time it takes for average American to consume average American's amount of flesh:
144.68 pounds per human / 210.8 pounds per year = .686 years, or 251 days.

Since we're going from all Americans (324.8 million or so) to one left standing, we can use a half-life calculator to skip some steps:

7097 days is 19.44 years. So assuming no population growth (and no one escapes!), everyone in America could eat everyone else, and be eaten themselves, in less than two decades. That's change you can believe in!

If you have better ways of calculating this, let me know and I'll update. Previous in Math: How Many Goats Does an iPhone Cost?