Unless you’re doing heavy veggie sandwiches that’s strange to me. I’ve packed my lunch my entire adult life, and sandwiches are the primary staple. Back when I ate meat I was able to mix it up between two different types of cold cuts day by day using the big containers and I can’t remember them ever going bad. Since I quit meat I just do peanut butter out of convenience and it’s similar. Occasionally a slice of bread or two goes bad but with the big whole wheat loaves from Aldi it’s an end piece and a few cents of spoilage. And all this is with me being the only one to eat these things.