Any tips to avoid snacking late at night?

I've been fasting for almost 3 years now. Just started switching into OMAD. This is not an issue related to OMAD but I was on vacation the last 3 months. I got used to staying up all night and snacking, but I barely gained 3kg/~6lbs because I wasn't eating many meals. Now that I'm back I find it hard to stop snacking at night. It's almost like an addiction now.