Having worked similar length shifts, I can totally relate, though mine are all day shifts, I’ve not any real experience of a night shift other than on-call. What works for me is balancing my blood sugar levels over the day, to avoid those peaks and troughs, and, boring as it is, staying away from the refined white carbs! In my experience, it’s easy to get to a (late!) lunch, and be so hungry that its easy to wolf down a white bread sub, packet of crisps and a few cookies brought in by a kind client in a few minutes. A situation like that for me is just absolutely game over, complete snooze-fest! I’m much better if I eat a decent breakfast with some protein (usually porridge or peanut butter on wholemeal or 50:50 toast) and keep some protein snack bars in my drawer for late morning when I’m starting to flag. Then for lunch I’ll have some soup or beans on wholemeal toast- these are things that don’t really need any prep in the morning, and I can keep a few tins at work so I’ve always got something for lunch. You might need something else in the afternoon, or if you are ok then you can have an evening meal of your choosing when it doesn’t matter if you get a big insulin rush after!