Flat bentos beat lunch bags in a backpack

The lightest and most compact lunch containers are flat bento boxes — about two inches thick — not insulated lunch bags.

The problem with most “compact” lunch bags is that they’re still bulky. They take up the whole bottom of a backpack. A flat box sits against the back panel or slides into a side pocket like a book.

Two that do this well: the Bentgo Kids and the Sistema Bento To Go. Both are roughly 7-8 inches long, 5-6 wide, and around 2 inches thick. The Bentgo Kids weighs about half a pound. The Sistema is cheaper and just as light. Either one disappears into a standard backpack.

If you want truly minimal — barely there — skip the compartment box entirely. A flat sandwich clamshell or a Stasher bag is the thinnest thing you’ll find. You lose the separate compartments, so packing gets less organized, but the footprint is basically zero. Collapsible silicone bentos sound like the answer but they’re heavier than plastic and not much thinner when packed. Not worth it.

Your kid’s backpack has better things to do than carry empty air.