“Gravity is what you get when you eat too much and too fast”

“Gravity is what you get when you eat too much and too fast” was included in a 1931 list titled “Boners: Being a collection of schoolboy wisdom, or knowledge as it is sometimes written, compiled from classrooms and examination papers.” The jocular one-line saying found renewed popularity on the Internet as early as 1983.
 
     
Google Books
Boners:
Being a collection of schoolboy wisdom, or knowledge as it is sometimes written, compiled from classrooms and examination papers
By Alexander Abingdon
New York, NY: Blue Ribbon Books
1931
Pg. 9:
Gravity is what you get when you eat too much and too fast.
 
5 October 1931, The Morning Oregonian (Portland, OR), pg. 7, col. 4:
BONERS
Boners are actual humorous tid-bits found in examination papers, essays, etc., by teachers.
(...)
Gravity is what you get when you eat too much and too fast.
 
18 November 1938, Scandia (KS) High News, pg. 3, col. 4:
Gravity is what you get when you eat too much and too fast.
   
Google Groups: net.jokes
Douglas Hoyt
8/2/83
(...)
Gravity is what you get when you eat too much and too fast.
   
Google Groups: comp.graphics
Ron Dippold
10/9/92
(...)
Gravity:  What you get when you eat too much and too fast.
 
Google Groups: rec.humor
Alan Silverstein
12/4/93
(...)
Gravity:  What you get when you eat too much and too fast.