When I was at university there was a lecturer who always bought two sandwiches and left one unopened on the table. I have no idea why he did this. He had a funny name too, I don't want to type his full name here but you will see it on a link here. His initials are DH.
http://www.ex.ac.uk/rbp/DeadCourses/BEM1004/Questionnaires/B EM1004Questionnaires.html
No one is fat for finishing their meals, they are fat because they have no self control.
Maybe it is a metabolism thing.