I can understand your concern, but since your question is regarding weight loss, you should have mentioned your present weight and also height.
anyways, the principle is simple to lose weight i.e., to have less calories than required in a day.
have 5 smaller meals rather than 3 full meals.
let one of those 5 meals be just of fruits and vegetables. drink lots of water, have 2 cups of green tea in a day and don't sleep immediately after food. let there be a gap of at least 2 hours between your meal and bed.
along with this, some amount of excretes daily will be needed to get good and sustainable results. do some cardio workout and core strengthening exercises.
yoga and meditation will help in weight loss as well as coping with the stress of working night shifts.
Dr. Anil Kumar Jain