I work at night .. gaining weight around the middle why ?

Weight Gain: Your weight gain could be related to your work schedule. However, it is probably more related to your eating habits and the amount of exercise that you get. It may be best to treat your working nights like your working days. That is, if your schedule permits, sleep eight hours prior to working your night shift, get up and have your breakfast, then go to work. Eat lunch at work, then have supper.