Philosophy

Frederick Hoelzel: The Glass-Eating Scientist

Frederick Hoelzel: The Glass-Eating Scientist
Date: 1889-1963

Frederick Hoelzel (age 27) following a 15 day fast.

As a teenager, Frederick Hoelzel adopted a strange method of weight-loss. He curbed his appetite by eating non-caloric food substitutes such as corn cobs, sawdust, cork, feathers, asbestos, rayon, and banana stems. His favorite meal was surgical cotton cut up into small pieces, which became part of his daily diet.

Later in his life, during the 1920s, while working as a researcher at the University of Chicago, Hoelzel put this talent for eating unusual substances to scientific use by ingesting a variety of inert materials in order to measure how quickly they passed through his intestines.

He scooped up gravel from the walkway outside the lab, swallowed it down, and recorded that it rattled out into his toilet fifty-two hours later. Steel ball bearings and bent pieces of silver wire each took approximately eighty hours to pass through him. Gold pellets moved at a leisurely pace through his intestines, only emerging after twenty-two days. Glass beads proved far quicker, speeding through his alimentary canal in a mere forty hours. His intestinal speed record was set by a piece of knotted twine that zipped through him in a mere one-and-a-half hours, aided along by a violent bout of diarrhea.

Hoelzel continued these unappetizing experiments daily for many years, well into the 1930s. In fact, Christmas was the only day of the year he took a break from this grim fare, to allow himself a small, but plain meal of entirely digestible food.

Frederick Hoelzel in 1955, age 65
(via Life Photo Archive)
The extreme diet left him skeletally thin. An unnamed reporter who visited the lab in 1933 wrote, "His hands are like those of an invalid, white, blue-linen and bony, his Adam's apple stands out from a scrawny neck, and his skin is colourless except for a network of fine blue lines, especially under his eyes."

Hoelzel never became a full professor, only attaining the rank of "Assistant in Physiology" at the University of Chicago. He was more widely known by the nickname the press gave him: The Human Billy Goat.