Nobody is asking leaders to die of starvation. Moreover dying needlessly only deprives the team from leadership,

However, the leader that feeds himself first shows by example that if people are hungry, they should take care of themselves instead of their team members.

There is a difference wearing an oxygen mask first. All airline pilots wear their oxygen mask before they drops it for the other passengers. But you can expect an uproar if the pilot forces his way to the exit in an emergency.