Yup. They usually end up eating J or F meals, or the cockpit crew food if the pilots don't want everything (cockpit crew usually have sandwiches or something loaded on specifically for them, not available to pax I'm pretty sure). And....I definitely have seen FAs keeping extras for themselves, and telling pax the choice is all gone. This is a no-no, but I've seen it happen have enough anecdotes and am sure it continues. I'm talking about even the availability of a first-choice meal, not seconds.