A threefold mother, who has used food banks while waiting for her first general loan payment, said she had "never felt so low".
At a food bank in Cardiff, the 37-year-old woman said she was worried that she would not be able to buy Christmas presents for her children.
A charity organization said that waiting at least five weeks for a first job could mean more people need help.
The Trussell Trust reports that the food bank recorded a 13% consumption. The British government said they were used for a variety of reasons.
"I have to say no to the children"
Ruth, not her real name, has worked all her life and lived relatively comfortably.
However, she recently lost her job and since she was a new general credit applicant, she was told to wait at least five weeks to receive her first payment.
With no savings and no alternative income, Ruth had to claim an upfront payment of £ 1,300 she received.
But almost everything was paid for rent and bills, leaving her with very little money to buy food for herself and children.
"It's Christmas time, I've always worked that way, and I'm not going anywhere for weeks, it's awful," she said.
"My kids can not have anything, I've never felt so bad, the kids definitely know it because I have to say no to them when they ask for things.
"I never thought in a million years, I would use a food bank."
What is universal credit?
It combines six benefits (income support, earnings-related unemployment benefit, earnings-related employment and support allowance, housing benefit, child and work tax credit) into one.
It's designed to make the benefits of claims easier. A one-off payment is made directly to the bank accounts of an applicant to cover the benefits to which they are entitled.
The plaintiffs then have to pay their expenses, such as the rent. It can be said by people whether they are working or not – but the payments decrease as you earn more.
The Trusell Trust announced that demand for emergency food packages in Wales had risen by 13% over the same period last year. Between April and September, nearly 49,000 food parcels were distributed for emergencies.
With the introduction of general credit risk, more people may need support, especially in the winter months with rising heating costs.
Helen Bull, the development director of the Trust's Cardiff Foodbank, said she was shocked by the "desperately sad" stories of the people.
"There was a man who came in the other day who said he could not afford a shampoo, so he used fairy fluid," she added.
Ms Bull said that the main reasons for using food banks are low income, delays and changes in benefits, as well as the collapse of relationships or illness.
The Department of Labor and Pensions announced that it has just announced further incentives to work, including the amount that applicants can earn before the payments begin.
This is in addition to other improvements such as 100% progress, said the spokesman.
He added, "The reasons why people use food banks are complex, so linking a rise to a specific cause is wrong."