“I don’t buy milk because it’s so expensive,” she said. “I don’t buy cheese.”

Officially called the Supplemental Nutrition Assistance Program, or SNAP, food stamps have long been a cornerstone of the federal safety net. Benefits, adjusted for income, are loaded monthly onto a government-issued debit card. Recipients say the money typically lasts a little more than two weeks.

“We don’t splurge,” Ms. Adams said, “and it doesn’t last.”

She shops at Save-A-Lot and cooks frequently with pasta, because it is filling. One recent evening, she baked a tray of mostaccioli, an Italian pasta, with meat and cheese. Hoping it would last for two meals, she had none herself.

“You hate to tell your child, ‘You can’t eat this, you have to save it for another day,’ ” she said.

For the Rigsbys, both 20, the priority is three meals a day for their son, Drake, who is 1. Some months they run out of milk. Mr. Rigsby, who is out of work with a knee injury, recently sold his truck for cash; his wife, Christina, works part time as a clerk at J. C. Penney. On the refrigerator in their sparsely furnished apartment is a calendar marked with the date — the 6th — that their card is refreshed. “FOOD!” it declares.

“When we got married, we told each other that we want to be able to sit down at the table and eat as a family,” Mrs. Rigsby said. “But we don’t really get to do that.”

In Washington, House Republicans propose cutting $40 billion more in food stamps over the next 10 years by imposing work requirements and eliminating waivers for some able-bodied adults. The cuts would push four million to six million low-income people, including millions of “very low-income unemployed parents” who want to work but cannot find jobs, off the rolls, according to the Center on Budget and Policy Priorities, a left-leaning research organization.

Even if approved in the House, the cuts would face strong opposition from Democrats in the Senate. But the arguments of Mr. Rector, the Heritage Foundation scholar, are gaining traction with conservatives on Capitol Hill. “I think food stamps have in the Republican mind become the symbol of an out-of-control, means-tested welfare state,” Mr. Rector said.