I gained my "Freshman Fifteen" picking marshmallows from Lucky Charms.
Here you have a 20 pound bag of the culprit. Marshmallows only.
I so wanted to believe boxes and boxes of Lucky Charms had been purchased and picked through.
I was worried (for my figure) to learn you can order them online.
"At CerealMarshmallows.com. Duh."
-Kristy (pictured below in the midst of telling me to hurry up and take the picture because the bag was really heavy)