How can mass media help poor and starving people?

They already do. They give them newspapers to wear as clothes.

Seriously, they raise awareness of poverty and give to charities. In some cases, they work to fix conditions that exacerbate poverty and hunger.

For instance, a news magazine program managed to raise money to get electricity delivered to Native Americans whose lands were still under an old government freeze order. That paved a way for them to have running water too.