Atef Abu Khater, 17, who was healthy before Gaza was gripped by war, lies in intensive care in a hospital in the north of the Palestinian enclave, suffering from severe malnutrition.

“He is not responding to the treatment,” said his father, A’eed Abu Khater, 48, who has been sheltering in a tent in Gaza City with his wife and five children. “I feel helpless,” he added in a phone call, his voice strained with grief. “We lost our income in the war. Food is unaffordable. There is nothing.”

Gaza’s hospitals have struggled since early in the war to cope with the influx of Palestinians injured and maimed by Israeli airstrikes and, more recently, by shootings meant to disperse desperate crowds as they surge toward food convoys or head to aid distribution sites.

Now, according to doctors in the territory, an increasing number of their patients are suffering — and dying — from starvation.

“There is no one in Gaza now outside the scope of famine, not even myself,” said Dr. Ahmed al-Farra, who leads the pediatric ward at Nasser Hospital in southern Gaza. “I am speaking to you as a health official, but I, too, am searching for flour to feed my family.”

The World Food Program, an arm of the United Nations, said this week that the hunger crisis in Gaza had reached “new and astonishing levels of desperation, with a third of the population not eating for multiple days in a row.”