Get an insulated food jar, not a 'leak-proof' Tupperware.

The best leak-proof lunch boxes for soups and curries are insulated food jars, and the safest bets are Thermos and Zojirushi ones.

Nobody makes a genuinely leak-proof plastic container with a clip-on lid. Clip lids bend, gaskets shift, and you see it in your bag the first time you hit a pothole. Insulated food jars solve this with a screw-on lid and a thick silicone gasket that locks everything in. You turn them upright, they stay upright, and that’s exactly how they’re designed to work.

For hot soups and curries, the Thermos Stainless King or Zojirushi Food Jar are the classics. Both keep food hot for hours and seal tight enough to be thrown in a backpack without a second thought. Zojirushi is usually easier to clean and better at keeping things hot; Thermos is slightly cheaper and just as reliable. Pick whichever is in stock.

If you’re carrying something like salad with dressing, or fruit, you don’t need insulation — just get an OXO Smart Seal container. They’re not meant for upright hot liquids, but for cold stuff they’re solid.

Just don’t trust a BPA-free plastic box with a locking tab to handle dal or pho. It’s a matter of time.

Your bag will thank you.