In past years, the farms south of here produced at capacity, everything from chickens to soybeans.

Alberto Troiani, 48 years old, still works the hog farm that his father, an Italian immigrant, founded in the 1970s. His business has now been battered by price controls, a shortage of supplies and criminal gangs.

The farm has gone from 200 female pigs, each producing a dozen piglets, to 50. Mr. Troiani can’t afford the high-protein feed and medicines he once used. Full-grown pigs now weigh 175 pounds instead of 240 pounds.

What is worse, he said, walking past half-empty pens, is seeing his pigs sometimes bite off the tails and ears of others.

“We used to send 120 to 150 pigs a month to slaughter,” Mr. Troiani said. “Now it’s 50, 60 animals, a joke.” He makes 93 cents per kilogram, or 2.2 pounds, of meat, he said, but needs $1.17 to make a profit. Since 2012, 82% of Venezuela’s pig producers have closed, and production has fallen 71%, according to industry representatives.

Mr. Troiani talked about leaving Venezuela with his mother, Yolanda Facciolini, 69 years old, who arrived from Italy in the 1960s. He said he would have no buyers: All around him, people are abandoning their farms. Thieves take what is left behind, he said—copper wire, tractors, weed killer.

The agricultural companies the government has taken over, including milk factories and distributors of fertilizer and feed, are closed or barely operating, according to economists and farm groups.

“The system is created so you can’t win,” said Alberto Cudemus, who heads the national association of pig farmers. “The government thinks its survival is in communism, not in us, not with production. And that’s where they’re wrong.”

Survival skills

Diogenes Alzolay, 65 years old, once had two small construction companies and later drove a cab. He is now trying to sell the freezers of the small store he once ran along with his books, lamps, photocopier and taxi.

On a recent day, Mr. Alzolay was frying sardines. To stretch the food they have, a couple of family members skip eating one day to leave enough for the others. Meals are sometimes the local corncakes known as arepas, vegetables, mangoes and the occasional canned fish.

“I’ve thought about running away, but I can’t do it because of our very little kids,” Mr. Alzolay said. “Getting to this extreme makes me want to cry.”

Nine in 10 homes said they don’t make enough money to buy all their food, according to the poll of living conditions. Nearly a third of Venezuelans, 9.6 million people, eat two or fewer meals a day, up from 12.1% in 2015, the poll found; four of out five in the nation are now poor.

Cesar Augusto Palma, 75 years old, lays out the grim arithmetic of high inflation on a fixed income. His pension is now worth about $10 a month, he said, enough to buy four boxes of milk.

His grown daughter and three grandchildren are financial dependents. Mr. Palma and his grandson Germain, 11 years old, eat less food to leave more for the two younger children. Germain’s once-thick hair is turning yellow.

“They need it more than me,” said Germain, who weighs 50 pounds instead of 70 pounds, about the average for a boy his age. Nearby, his brothers, Cesar Augusto, 10 years old, and Angel Jose, age 4, try to fly a handmade kite.

“I am hungry,” Germain said. “I feel like a pain in my belly.” Asked his favorite meal, he said, “Arroz con pollo,” rice and chicken, which he last ate in 2015.

At the Domingo Luciani Hospital in Caracas, Ms. Planchart cried when she recalled the ways she tried to feed baby Jean Pierre and her four other children. She went through trash bags, searching for bits of corn or bread free of maggots.

“I’d stand there and say, ‘I can’t do it,’ ” she said, worried of being seen by neighbors. “I said to myself, ‘If I don’t do it, this, what will I take to my children?’ ”

Ms. Planchart had a string of jobs: cashier, hair salon worker, cook. Then the work disappeared; inflation and food shortages made everything worse. At one point, she said, a neighbor cooked a dog.

As she watched Jean Pierre grow thinner and then stop moving, she decided to seek help from Dr. Machado and other malnutrition experts at the hospital. The doctors don’t have vitamins, antibiotics or serum for sick babies.

“We’re not feeding him well in this hospital,” Dr. Machado said. “No boy like this is going to get better with bananas and cheese.”

Ms. Planchart, meantime, rocked Jean Pierre in her arms, a balm for both.

“He hasn’t fully recovered,” she said of her baby, who now has chickenpox. “The idea is for him to get his weight up and that we get his metabolism to where it should be. But he’s delicate.”