This is what works for me:

At the END of the briefing, if I know we’re supposed to get crew meals, I say, “hey, me and the copilot hadn’t eaten this morning/all day/etc. we see we’re supposed to get crew meals on this flight. Can you check and make sure they’re loaded? When you’re done with service, can we do a break/pass them up/etc.”

Say it with a smile, set the tone, make them aware, say it last (law of recency). 60% of the time it works every time.