Good Luck with your weigh in tomorrow, I know you will get a great result!. I don't do shift work but also work anywhere between an 8 and 17 hour shift - I am a chef - so know it is really hard when it's a long long day. When I did a 17 hour last week, I had a porridge in the morning, water and soup for lunch, a broth in the afternoon and kept a bar to nibble on through the day, and ended with a shake when I finally got home. It seemed to keep me going.
Good luck with your weigh in Slimsea, I am also starting back today after loosing 40lbs and putting it all back on apart from 6lbs. I'm not going to beat myself up about it, but I am going to get back on the wagon and do it this time.