Hard plastic beats insulated bags for chip protection

A thin-walled polypropylene bento container is the lightest lunch box that will actually keep chips and crackers from getting crushed.

Insulation is the enemy here. Any lunch box with rigid sides and insulation built in has a thick foam or plastic shell, and that weighs real money. A typical insulated lunch bag with structured walls comes in around a pound. A simple locking plastic container — the kind Sistema or Lock & Lock make — is often under 200 grams and the walls are still stiff enough that a bump won’t turn your chips into crumbs.

If you need to keep food cold, keep the chips in a small rigid container inside your regular soft lunch bag. That combo is still lighter than buying a hard-sided insulated box, because you only pay the weight penalty for a little chip box instead of a whole insulated shell.

Rigid sides and light weight pull in opposite directions. Pick the lightest thing with walls you can’t flex with one hand, and that’s almost always a plain plastic bento box.

Your chips are fragile. Your lunch box doesn’t need to be a tank.