The Times went to South Sudan to document the extent of hunger as food grew scarce. This year is expected to be the worst yet, as millions potentially face acute malnutrition.

JUBA, South Sudan — The hunger season came early this year.

By February, once seen as a time of plenty, Nyabolli Chok had run out of food for her three children in their village here in South Sudan. She knew they had to leave.

“We were eating leaves off of trees,” she said, describing how she boiled them into a watery soup.

“Ron reath,” she said — her words for the hunger season. South Sudan’s dozens of ethnic groups use different names for the months when food becomes scarce until the next harvest. But the fears are the same: malnutrition, disease, even death.

And this year is expected to be the worst yet.

More than four years of civil war — most of this young country’s existence — have chased millions from their homes, leaving countless farms abandoned. The economy has been obliterated. Fighting has overcome some of the nation’s most productive land. Food prices are ruinously high.