American comedian Jay Leno is credited with a popular Thanksgiving joke:
 
“You can tell you ate too much for Thanksgiving when you have to let your bathrobe out.”
 
Leno probably said it on television’s The Tonight Show with Jay Leno in November 2004. The joke was printed in a 2005 book and in November 2005 articles.
 
     
Wikipedia: Jay Leno
James Douglas Muir “Jay” Leno (/ˈlɛnoʊ/; born April 28, 1950) is an American comedian, actor and television host. He was the host of NBC’s The Tonight Show with Jay Leno from 1992 to 2009. Beginning in September 2009, Leno started a primetime talk show, titled The Jay Leno Show, which aired weeknights at 10:00 p.m. ET, also on NBC.
 
After The Jay Leno Show was canceled in January 2010 amid a host controversy, Leno returned to host The Tonight Show with Jay Leno on March 1, 2010. He hosted his last episode of The Tonight Show on February 6, 2014. That year, he was inducted into the Television Hall of Fame.
   
Google Books
It’s a Man’s World:
800 Jokes from the Guy’s (Warped) Point of View
By Judy Brown
New York, NY: Barnes & Noble Books
2005
Pg. 111:
You can tell you ate too much for Thanksgiving when you have to let your bathrobe out. — Jay Leno
 
THE BEST THANKSGIVING JOKES (AND ACTION!)
By judybrowni
Thursday Nov 24, 2005 · 2:41 PM EST
To get you through the holiday, I offer up a three-course meal of the best Thanksgiving jokes (culled from the joke books I edit, including The Comedy Thesaurus (Quirk Books).
(...)
You can tell you ate too much for Thanksgiving when you have to let your bathrobe out—Jay Leno
 
Google Groups: I Hate Bush Fan Club
Best Thanksgiving jokes
.(JavaScript must be enabled to view this email address)
11/24/05
(...)
You can tell you ate too much for Thanksgiving when you have to let your bathrobe out—Jay Leno
 
25 November 2005, Akron (OH) Beacon Journal, “Porter’s People” by Mickey Porter, pg. A2, col. 6:
You can tell you ate too much for Thanksgiving when you have to let your bathrobe out.
—Jay Leno, on NBC
 
26 November 2009, Ithaca (NY) Journal, “Danby Town Talk: Be grateful this Thanksgiving:Take time to help the needy” by Gay Huddle, pg. A6:
Happy Thanksgiving to everyone, and keep in mind Jay Leno’s words, “You can tell you ate too much for Thanksgiving when you have to let your bathrobe out!”
 
Google Books
The 2,320 Funniest Quotes:
The Most Hilarious Quips and One-Liners from AllGreatQuotes.com
Compiled by Tom Corr
Berkeley,CA: Ulysses Press
2011
Pg. 390:
You can tell you ate too much for Thanksgiving when you have to let your bathrobe out.
—Jay Leno
 
Google Books
Laughter, the Best Medicine: Holidays
Ho, Ho, Ha! The Merriest Jokes
By Editors of Reader’s Digest
New York, NY: The Reader’s Digest Association, Inc.
2012
Pg. ?:
“You can tell you ate too much for Thanksgiving when you have to let your bathrobe out.” —JAY LENO