The genesis for this piece comes from a couple of books I wrote about 10 years ago: Your Brain: The Missing Manual and Your Body: The Missing Manual. I had my dream job with them — a chance to talk about all the quirky and just plain weird things going on inside our bodies. (I have an excerpt from one of them on Medium that talks about illusions.) When I finished, I had collected a bunch of additional ideas that I wanted to explore but couldn’t fit in the book, and the calorie system was one of them.

One thing that really caught my attention was when a well known health/diet author counted how many calories were in a glass of orange juice, and calculated how many pounds you would gain in a year if you drank one extra glass of orange juice every night. This fascinated me, because it’s clear insanity to anyone who knows anything about how human bodies work. Somehow, calories gave us a system of numbers and a facade of math that let us feel comfortable in making some very dubious extrapolations.

If you browse through my other “Science of Eating” articles, you’ll see that I mostly write about science. It was only when I started writing about the calorie system that I began to talk about a second theme — how it conveniently benefits the food industry — and I think that’s what gave this article more appeal to many more people.

TLDR: This story was kicking around my brain for a long while, and I decided to write it up one day for fun! Feel free to ask follow-up questions here or contact me at matthew at prosetech.com.