Jean Anthelme Brillat-Savarin (1755-1826), in the book Physiologie du Gout (1825), wrote “Tell me what you eat, and I shall tell you what you are,” often interpreted as “you are what you eat.” This was figurative and not meant literally; one does not become an apple or a donut or a “skinny person” by eating such things. 
 
‘I bought ready-to eat apricots. They worked. I was ready to eat apricots. James Acaster. #gb12” was posted on Twitter on August 27, 2012. “They say you are what you eat,which is true because when I bought ready to eat apricots,I was ready to eat apricots” was posted on Twitter on October 13, 2012. The joke is from English comedian James Acaster. Other foods—besides apricots—have sometimes been used.
       
“They say you are what you eat. Today I bought some ready to eat chicken…” is a similar joke.
     
 
Wikipedia: James Acaster
James William Acaster (/ˈeɪkæstər/; born 9 January 1985) is an English comedian originally from Kettering, Northamptonshire and now based in London. He has performed for several consecutive years at the Edinburgh Festival Fringe and won two Chortle awards in 2015. Acaster has appeared on several panel shows, including Mock the Week, and has a 2018 Netflix show entitled Repertoire, consisting of four hour-long stand-up comedy performances.
         
Wikiquote: Food
Dis-moi ce que tu manges, je te dirai ce que tu es. Tell me what you eat, and I shall tell you what you are.
. Jean Anthelme Brillat-Savarin, Physiologie du Gout (1825); tr. M. F. K. Fisher, The Physiology of Taste: Or Meditations on Transcendental Gastronomy (1949)
. Variants:
..Der Mensch ist, was er ißt. Man is what he eats.
..Ludwig Andreas Feuerbach, Die Naturwißensschaft und die Revolution [Natural science and the revolution] (1850), repeated in Das Geheimnis des Opfers, ober der Mensch ist was er ißt [The mystery of sacrifice, or man is what he eats] (1862)
..You are what you eat.
..Victor Lindlahr, You Are What You Eat: how to win and keep health with diet (1942)
   
Twitter     
Dean Ayres
@ayresnograces
‘I bought ready-to eat apricots. They worked. I was ready to eat apricots. James Acaster. #gb12
2:55 PM - 27 Aug 2012
 
Twitter
b e c k
@fire_crackerr
They say you are what you eat,which is true because when I bought ready to eat apricots,I was ready to eat apricots
6:20 AM - 13 Oct 2012
   
Twitter
Scott
@sirish92
“They say you are what you eat and their right. I brought ready to eat apricots and I was ready to eat apricots” 😂
9:21 PM - 18 Dec 2012
   
Twitter
meg
@megan2304
‘i bought ‘ready to eat apricots’, they say you are what you eat and they’re right.. cos I was ready to eat apricots’ made me laugh too much
1:38 PM - 21 Aug 2013
   
Twitter
Liz Evans
@theskyisblue_
‘they say you are what you eat so today I went to Tesco’s and bought ready to eat peaches and when I left I was ready to eat peaches’
5:40 PM - 23 Aug 2013
     
tumblr.—diaryofacomic
*James Acaster’s joke was “They say you are what you eat, which is true because I purchased some Ready To Eat Peach Slices and when I did, I was ready to eat peach slices”.
 
I couldn’t find a video. Sadly, the one I bookmarked has been taken down.
Nov 10, 2014 8:05 am
 
Twitter
MICZ
@GenesisMICZ
They say you are what you eat and I just picked up a ready to eat lasagne, so I’m ready to eat lasagne
3:34 PM - 4 Dec 2015
   
Twitter
Adam
@AdamTodd310389
Bought some ready-to-eat conference pears, because you are what you eat, and I’m ready to eat conference pears.
11:00 AM - 11 Feb 2016
 
YouTube
James Acaster - Mock The Week Compilation
DelphicForeigner
Published on Oct 8, 2016
A compilation of all of James Acaster’s stand-up round performances on Mock the Week from series 13 through to series 15. Enjoy!
8:18
“I’m trying to eat more healthily lately. I bought some ready to eat apricots this week. They say you are what you eat, which is true ‘cause as soon as I bought the ready to eat apricots I was ready to eat apricots.”
(From Mock the Week, series 14, episode 10, originally aired in the UK on October 1, 2015.—ed.)
 
Reddit—Jokes
They say you are what you eat
submitted October 27, 2016 by WillieJenkins
So I bought myself some “ready to eat Apricots”
And after I bought them I was indeed, ready to eat Apricots.
   
Twitter
SmexyZexy5 [DBNM]
@JKZEXY5_DBNM
They say you are what you eat! - when you buy ready-to-eat meals, you’re ready-to-eat meals!
3:39 PM - 8 Jun 2017
 
YouTube
James Acaster Stand-Up 06/20/17 - CONAN on TBS
Team Coco
Published on Jun 21, 2017
The only thing James enjoys more than ready to eat apricots is the “sexy battery” taste of Dr. Pepper.
0:20
“I bought some ready to eat apricots the other day. You call them dried apricots, but we call them ready to eat apricots because that’s how much we love apricots. (...) Bought some ready to eat apricots the other day. Trying to be more healthy. They say you are what you eat, which is true ‘cause after I bought the ready to eat apricots I was ready to eat apricots.”
 
Twitter
Dan Flan Van Dam
@PennyOnThaDolla
They say you are what you eat, it’s true. I bought some “ready-to-eat” guacamole today and that’s what I became: ready to eat guacamole.
1:40 PM - 9 Jul 2017
 
Twitter
Georgie Wright
@Georgie__Wright
if you are what you eat then i am pret a manger, which technically means i am always ready to eat. sounds about right i guess
2:37 PM - 29 Nov 2017
 
Twitter
Birchley Heath Bikers
@BirchleyB
It’s true when they say you are what you eat. Because when I brought this packet of ready to eat apricots, I was ready to eat apricots.
5:49 PM - 21 Jan 2018
 
Twitter
Kieran
@KieranG_TK
They say you are what you eat. I am ready to eat rich and creamy avocados
11:01 AM - 5 Apr 2018
 
Twitter
Nessy
@nessywhu
“bought some ready to eat apricots the other day & it’s true what they say, you are what you eat bc as soon as i bought ready to eat apricots, i was ready to eat apricots… they also came in a resealable bag; bc not everybody is as ready to eat apricots as they think they are”
1:24 PM - 10 Apr 2018 from Rossington, England
 
Twitter
Joe
@_Joeheaton_
Spot on when they say “you are what you eat”  cos I just bought some ready to eat watermelon and low and behold I was ready to eat watermelon. Absolute Madness
4:24 PM - 5 May 2018
 
Twitter
Fourdan
@J0rd4nic
I never understood the phrase you are what you eat until right now. I’ve never been a sandwich or an apple before. But when I’m eating Tescos ready-to-eat apricots I am in fact ready to eat some goddamn apricots. Crazy how things work out
10:20 AM - 22 Jun 2018
 
Twitter
Emily Sturgess
@EmilySturge
As @JamesAcaster says, you are what you eat, and I find that I am Ready To Eat Nectarines. Well, *a* nectarine… #hescomedygold
7:26 AM - 13 Jul 2018