I only snack on a digestive if my levels are on the low side and I don't feel safe enough to go to bed but I'm a Type 1 on insulin, if you aren't on a hypo causing medication then I don't understand why people feel the need to snack before bed
Edited to add
Ah I see your on Glic, is it because your experiencing lower levels when you test before bed?
xx
I see you are on Gliclazide, which might mean you need to eat to counteract its effects - if you are low then cheese and crackers or a couple of plain biscuits would be an easy option.