Simple changes can help. After 3 years of mandatory OT, I put on some weight. I was gone 13-15 hrs/day, 6 days/wk. I'd eat junk from the vending machines and get home at midnight and eat a sandwich and some chips. I wouldn't do too much on my off time because I was drained. I finally had enough when the OT stopped. I started making little changes that really help. I pack a salad and fruit for lunch. I get home and have steamed carrots, an apple or sliced cucumbers(good substitute for chips if you want something crispy). I'm only losing about 3 pounds/wk, but it's better than nothing and I hate exercise. If I stopped eating junk on weekends, I could probably lose 5/wk.