“Exercise? I thought you said extra fries”

“Exercise? I thought you said extra fries” is a jocular saying that has been printed on T-shirts and posters. “I keep getting exercise and extra fries mixed up” was cited on Twitter on October 25, 2011.
   
“Exercise? I thought you said extra fries” was cited on Twitter on December 6, 2012.
   
“Exercise? I thought you said extra rice” and “Exercise? I thought you said extra slice” are similar sayings. 
       
 
4 November 2002, Star-Tribune (Minneapolis, MN), “Musings; Getting there; Sometimes the journey is as satisfying as arriving at the destination” by Jim Foti, Pg. 12E:
Extra? Extra what, I asked, and he repeated it several times. It sounded like “extra fries,” but he hadn’t ordered any fries. Eyes? I felt terrible for not understanding.
 
Then the light bulb clicked on: exercise. He was proud, for perhaps the first time in his life, that he’d gotten so much exercise.
     
Twitter
fatgirlproblems
‏@fatgirlproblms
I keep getting exercise and extra fries mixed up #FGP
9:12 PM - 25 Oct 2011
   
New York (NY) Times
The Haves’ Children Are Healthier Than the Have-Nots’
By KATHARINE MIESZKOWSKI DEC. 24, 2011
(...)
Robert O’Brien, Sycamore Valley’s physical education specialist, who favors shorts even when the temperature dips into the 40s, is fond of slogans like “exercise, not extra fries.”
     
Twitter
Ana Matute
‏@deadelectron
yyeehaw: exercise? more like extra fries. http://tmblr.co/ZUXW5xSSorcq
6:03 PM - 30 Aug 2012
 
Twitter
nicole
‏@accolou
exercise
extracise
extracies
extrafies
extra fries
3:13 PM - 7 Nov 2012
 
Twitter
Whitney
‏@FallofWhin
Kailin: Exercise? I thought you said extra fries. I got excited.
1:12 PM - 6 Dec 2012
 
Twitter
Bryn
‏@Bryn_w3
Exercise
Exercis
Exerci
Exerc
Exer
Exe
Ex
Extra fries
4:56 PM - 9 Apr 2013
 
Twitter
me
‏@mkenzB
Oh EXERCISE?! I thought you said extra fries…
9:34 PM - 9 Apr 2013
 
Twitter
Heather Rice
‏@HeatherMacRice
“Exercise? I thought you said extra fries.” 😂 #haha #fitfunny #instafit #fitness #health… http://instagram.com/p/gg32PDRarX/
6:15 PM - 9 Nov 2013
 
Funny Status
Exercise? Oh, I thought you said extra fries! No, I’m good.
April 10, 2015