Tourist Inventory Slots
With the exciting (and awesome) new update 1.11, tourists have been given inventory slots. I needed to make use of one to shuffle things around. While they work like any other Kerbal's inventory, their slots are emptied when loading a save (or, the contents are not saved and therefore not loaded - take your pick).
This is easily reproduced...
Put anything into a tourists inventory slot.
Save the game.
Load that save.
The tourists inventory is empty.
I do have two mods running (Kerbal Engineer Redux and Trip Planner), though I doubt they are the cause.
I have not attempted to reproduce this by removing the mods first.
This may not explain missing snacks, but it does explain what happened to my missing work-lamp and parachute.