“Why did the woman wear a helmet at the dinner table?”/“She was on a crash diet.”

A riddle about a “crash” diet (an extreme diet) is:
   
Q: Why did the woman wear a helmet at the dinner table?
A: She was on a crash diet.

   
Forms of the riddle have been cited in print since at least 1998 and 2004.
 
”#cornyjokes why did the lady wear a helmet when she ate??..... She was on a crash diet” was posted on Twitter by Lee McCloud, III on May 31, 2012. “Q: why did the lady wear a helmet every time she ate? A: she was on a crash diet” was posted on Reddit—Jokes on December 9, 2018.
 
       
23 November 1998, Sacramento (CA) Bee, “Serve Up the Jokes” by Alison Roberts, pg. C2:
Why did the man wear a helmet to the Thanksgiving table? Because he was on a crash diet.
   
12 December 2004, Sunday Telegraph (Surry Hills, New South Wales), “The Funday Telegraph” by Matt Frilingos, pg. S18:
Why did the woman wear a helmet at the dinner table?
She was on a crash diet.
   
Google Books
A Recipe for Success:
Lizzie Kander and Her Cookbook

By Bob Kann
Madison, WI: Wisconsin Historical Society Press
2007
Pg. 90:
Why did the woman wear a helmet at the dinner table?
She was on a crash diet.
 
Twitter
CircusMagic
@CircusMagic
Why did the woman wear a helmet at the dinner table? - She was on a crash diet.
2:03 PM · Jun 14, 2009·Twitter Web Client
   
Twitter
Antonee
@AntBee82
soooo um….I’m kinda bored….Why did the lady wear a helmet to dinner? she was on a crash diet! LOL hahahahaaa
10:26 PM · Aug 24, 2009·Twitter Web Client
   
Twitter
Neah
@monorailgirl
Why did the woman wear a helmet to dinner? SHE WAS ON A CRASH DIET.
7:17 PM · Sep 27, 2009·Twitter SMS
 
Google Books
Laugh-Out-Loud Jokes for Kids
By Rob Elliott
Grand Rapids, MI: Revell
2010
Pg. 36:
Q: Why did the lady wear a helmet every time she ate?
A: She was on a crash diet.
     
Twitter
Q101 FM - Merritt
@Q101Merritt
Brian’s Joke of the Day: Why did the woman wear a helmet at the dinner table? She was on a crash diet! http://bit.ly/cMgfSE
10:15 AM · May 19, 2010·Facebook
   
Twitter
Daily Groaner
@DailyGroaner
Q: Why did the woman wear a helmet at the dinner table? A: She was on a crash diet.
3:00 PM · Jun 2, 2010·Twitter Web Client
   
Twitter
Jake Scroby
@Scrobez
#jokeoftheday
Why did the woman wear a helmet at the dinner table?
She was on a crash diet.
4:25 PM · Feb 6, 2012·Twitter for iPhone
   
Twitter
Lee McCloud, III
@leef3aka_Slick
#cornyjokes why did the lady wear a helmet when she ate??.....
She was on a crash diet. Kmsl
1:16 AM · May 31, 2012·Twitter for iPhone
 
Explain the Joke
Dangerous Diet!
Posted on May 22, 2014 by stfleming
Q: Why did the lady wear a helmet every time she ate?
A: She was on a crash diet!
 
Explanation: A crash diet is a diet where a person loses a lot of weight in a short amount of time: lose weight fast.  A helmet is protection for your head when you are playing a sport or working.
     
Twitter
Vannetta Chapman
@VannettaChapman
Joke for the day.
Q. Why did the lady wear a helmet every time she ate?
A. She was on a crash diet.
from Laugh-out-loud jokes.
8:00 AM · Sep 25, 2014·Buffer
 
Twitter
Tony Blackburn
@tonyblackburn
I saw a woman wearing a helmet having dinner in a restaurant the other day…..she was on a crash diet.
3:19 AM · Jan 20, 2016·Hootsuite
 
Google Books
DC Super Heroes School Jokes
By Michael Dahl and Donald Lemke
North Mankato, MN: Capstone Young Readers
2018
Pg. 54:
Why did The Flash wear a helmet in the school lunchroom?
He was on a crash diet!
 
Reddit—Jokes
Posted by u/liltrigger December 9, 2018
Q: why did the lady wear a helmet every time she ate?
A: she was on a crash diet
   
Twitter
Daily Comedy
@QuirkyMessages
Why did the lady wear a helmet every time she ate? She was on a crash diet!
7:56 PM · Dec 8, 2020·Twitter for iPad