“Birthdays are nature’s way of telling us to eat more cake” is a jocular line that has been printed on many posters. ““Birthdays are nature’s way of telling us to eat more cake and ice cream” was cited in print in 1998. “Birthdays are Nature’s way of telling us to eat more cake!” was cited in 2001.
 
It’s not known who authored the saying. Edward Morykwas was credited on Twitter on March 29, 2009, but this is well after the saying had first been recorded.
 
   
Google Groups: mlist.net-happenings
NET-HAPPENINGS Digest - 2 Oct 1998 - Special issue (#1998-665)
Automatic digest processor
10/2/98
(...)
Date:  Fri, 2 Oct 1998 11:47:34 -0500
From:  Gleason Sackman

Subject: LISTS> Surprise Party - free fact and fun email newsletter
(...)
Here’s your invitation to the Surprise Party! An amusing five-day-a-week newsletter that tells you who’s celebrating a birthday, some birthday trivia, and fun party-time information! Everyone else gets older, while you get amused!  “Birthdays are nature’s way of telling us to eat more cake and ice cream. Blowing out candles is just a perk.” Written and produced by The Birthday Girl.
     
Google Groups: alt.2eggs.sausage.beans.tomatoes.2toast.largetea.cheerslove
...and the birthday girl is…..
Viva
5/23/01
>From: “~Kathy~” .(JavaScript must be enabled to view this email address)
>Date: 5/23/01
>Hippo birdies to you ......  Lisa !!!
From me too! Remember…Birthdays are Nature’s way of telling us to eat more cake! Be kind to yourself, have fun!
 
Google Books
Read This; It’s Funny!!
A Laughable E-Mail Collection
By Carl E. Knox
Portland, OR: OCGI
2003
Pg. 177:
Birthdays are nature’s way of telling us to eat more cake.
 
Google Books
Healthy Cooking for Children:
52 Brilliant Ideas to Dump the Junk
By Mandy Francis
Oxford: The Infinite Ideas Company Limited
2006
Pg. 203:
‘Birthdays are nature’s way of telling us to eat more cake.’
Unknown author
 
Twitter
Órlaith
‏@IcyJadeXOXO
@aangel Birthdays are nature’s way of telling us to eat more cake, Enjoy yours! Happy Birthday!☺
1:59 AM - 5 Feb 2009
 
Twitter
Maurisa C
‏@therealrisirose
Birthdays are nature’s way of telling us to eat more cake.
—Edward Morykwas
3:06 PM - 29 Mar 2009
 
Twitter
Marcy Hogan
‏@mightymarce
#Etsy Shop Update!  New listing: Birthday Card http://bit.ly/4tky “Birthdays are nature’s way of telling us to eat more cake”
6:11 PM - 3 May 2009
 
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. 60:
Birthdays are nature’s way of telling us to eat more cake. —Anonymous