So, I found this great card on http://robertsabuda.com/popmake/index.asp
which has a bunch of fun pop-up how-to's with downloadable patterns.
So, my friend is a diabetic, and feels a need to eat copious amounts of apples, specifically 3 a day for lunch. And in this case 'low' refers to being low on sugar, when you should eat simple sugars, and being in a less than fantastic mood. So, I can make tasteless jokes into epic birthdate anniversary cards:
I used file folders from work to make the card: made an envelope out of a red folder.