Here is what a friend from another forum told me... it really helped to put things into a different perspective for me:

You know, JJJ, my dad told me a story 2 days ago about when some girl first turned him and his friend on to speed. He said her words were "I just want you guys to know I'm only doing this because I'm miserable and I want some company." Addicts want company. You say your coworkers all eat candy and pizza etc.. that might be your answer. It's not jealousy, they are losing a companion and feel probably both betrayed and abandoned.