And interestingly, drinking is the opposite - consuming liquid kills thirst immediately, and it won't come back for ~20 minutes even if you still need hydration.

Both systems make sense, since you can hydrate in ~60 seconds but might need to stay hungry for ~10 minutes after you start eating. But they can both cause problems: hunger by prompting fast eaters to overeat, and thirst by letting dehydrating things like liquor satiate you.