If something is described as providing food for thought, it’s worth seriously thinking about or considering.
A well-made documentary on homelessness is likely to give you food for thought, as is your decision about where to go on a long-awaited vacation. Anything that gives you a reason to stop and ponder is food for thought. It’s an expression that’s been around in its current form since the nineteenth century, apparently taking the idea of digestion and transferring it from the stomach to the brain.
anything that provides mental stimulus for thinking