Olestra (en.wikipedia.org)

Back in the days before blogs was a word, someone had put up a rather hilarious page describing their experiment with Olestra.

Their question was: given that supposedly Olestea isn't picked up by the body, does it just pass through? And being an oily substance, would it just leak?

So they ate a lot of Pringles with Olestra each day, and took pictures of their underwear each day, keeping the same pair throughout to optimize evidence gathering. The page had a day-by-day account.

Results did indeed point to some going straight to the underwear, but IIRC it wasn't a massive amount.

Was written quite vividly too, which added to the whole experience.

In my first year of undergrad biology, we had an assignment pertaining to Olestra.

While I remember a lot of what I learned in undergrad, the only words from any course that I recall verbatim are from that assignment:

“Greasy, hard-to-wipe-off fecal matter.”

With 10% less anal leakage!