Your lunch box isn't keeping anything fresh. The containers are.

No lunch box keeps food fresh for five days — the fridge does that — but airtight glass containers with locking lids are what actually keep meal-prepped food tasting good by Friday.

The insulated bag you carry to work is just transport. Freshness comes down to the seal. Plastic containers with flimsy snap lids let air in, absorb last week’s chili, and stain permanently. Glass doesn’t have any of those problems. Look for the ones with four-side locking clips and a rubber gasket — Glasslock, Pyrex Simply Store, IKEA’s 365+ line, or any generic glass prep set with decent reviews. Two-section compartment versions are the sweet spot: protein plus a side without everything touching, and you’re not washing six tiny dishes a day.

Also be honest about what actually survives five days. Cooked