“Swallow your pride occasionally. It’s non-fattening” (or “not fattening”) is a saying that has been printed on many images. “Pumpkin Center Charlie says swallow your pride occasionally. It won’t give you indigestion” was printed in a Missouri newspaper in 1955.
   
“Swallow your pride occasionally. It’s non-fattening.—Frank Tyger” was cited in print in 1968. Brooklyn-born editorial cartoonist Frank Tyger (1929-2011) wrote for the Trenton (NJ) Times.
     
     
Welcome to the World of TYGER
Frank Tyger   -  A Brief Biography
Frank was born on December 24, 1929 in Brooklyn, New York to Belle and Joseph Tyger
(...)
In 1962 James Kerney Jr., then editor and publisher of The Trenton Times, offered Frank the job of his dreams—editorial cartoonist.  For the next 34 years, Frank worked for The Times drawing these cartoons, assuming other responsibilities including Promotion Manager, and writing a weekly Monday column for the paper.  During this time, he continued to pursue his lifelong interest in authoring quotes and puns which were published nationally in magazines such as Reader’s Digest, Forbes, Editor and Publisher and the Saturday Evening Post.
(...)
On May 2, 2011 Frank passed away after his 15-year battle with Parkinson’s Disease.
 
15 February 1955, Maryville (MO) Daily Forum, “Here and There,” pg. 1, col. 1:
Pumpkin Center Charlie says swallow your pride occasionally. It won’t give you indigestion.
       
21 November 1968, Newark (OH) Advocate, “Quips & Quotes,” pg. 4, col. 4:
Swallow your pride occasionally. It’s non-fattening.—Frank Tyger.
   
22 February 1969, Hartford (CT) Courant, pg. 9, col. 6:
Swallow your pride occasionally. It’s non-fattening.—Frank Tyger.
 
27 October 1969, The Times-Picayune (New Orleans, LA), “Remoulade” by Howard Jacobs, sec. 1, pg. 13, col. 2:
CALORIE COUNT….SWALLOW YOUR PRIDE OCCASIONALLY…IT IS NON-FATTENING.
   
5 February 1970, Seattle (WA) Times, “Quotable Quotes,” pg. A13, col. 1:
Swallow your pride occasionally. It’s nonfattening.—Frank Tyger.
 
Google Books
14,000 Quips & Quotes:
For Speakers, Writers, Editors, Preachers, and Teachers
By E. C. McKenzie
Grand Rapids, MI: Baker Book House
1990, ©1980
Pg. 421:
Swallow your pride occasionally — you’ll find it’s nonfattening.
 
Google Books
The Complete Book of Practical Proverbs & Wacky Wit
By Vernon McLellan
Wheaton, IL: Tyndale House Publishers
1996
Pg. 196:
Swallow your pride occasionally, and console yourself with the knowledge that it is 100 percent calorie free.
   
Google Books
Words from the Wise:
Over 6,000 of the Smartest Things Ever Said
By Rosemarie Jarski
New York, NY: Skyhorse Publishing
2007
Pg. ?:
PRIDE
Swallow your pride occasionally. It’snot fattening.
Frank Tyger
 
Twitter
slick_seneca‏
@slick_seneca
Swallow your pride occasionally, it`s not fattening. by Frank Tyger
12:10 PM - 22 Mar 2008
 
Twitter
Famous Quotes‏
@experiencedquot
Swallow your pride occasionally, it’s non-fattening. -Unknown
1:37 PM - 18 Jul 2017