Desperate Palestinians clutching pots and plastic buckets scrambled for rice at a charity kitchen in Gaza City on Saturday, a day after the United Nations declared a famine in the war-battered territory.

Israel has called the United Nations' declaration of famine in parts of Gaza an "outright lie," but multiple U.N. bodies, more than 100 humanitarian groups, and several of Israel's own allies have warned for months that the war and Israel's restrictions of food into Gaza are causing starvation among civilians.

An announcement of famine — as has now happened regarding Gaza — is a complicated decision. Here's what must be considered before such a declaration is made.