By Sarah Dickins & Steve Duffy
BBC Wales
People are having to eat pet food while others try to heat food on a radiator, a community worker with 20 years' experience has said.
Mark Seed now runs a community food project in Trowbridge, east Cardiff.
BBC Wales analysis of new Census data suggests six of Wales' most deprived communities are in the city.
A charity warns that struggling households do not just appear in areas long associated with poverty and policy needs to focus on people not places.
Trowbridge lies in what Mr Seed calls an "arc of poverty" from east to west of the Welsh capital, with issues endemic in his area.
"I'm still shocked by the fact that we have people who are eating pet food," he said.
"[There are] people who are trying to heat their food on a radiator or a candle.
"These are shocking kind of stories that are actually the truth."
"Cardiff is a flourishing city however there are pockets of deprivation which are simply not acceptable."
Mr Seed said people were not being paid enough to afford the essentials, with the cost of living crisis pushing prices way up "so that everybody is squeezed or they just can't afford it".
"What they are telling us is that they are working every hour they can," he added.
The Pantry offers good quality food at very low prices to more than 160 members.
One of them is Elizabeth Williams, 54, who says the project "makes a lot of difference" and brings people together but times were still hard.
"I usually go without to try to make things better in my house," she said.
She and her partner are not working, while her son lives with them and works long hours.
"Even with my son working - and he contributes as well - it's difficult because he has to live as well and he's got needs. He has got several things wrong [with him] and he's waiting for surgery."
[article continues with statistics about poverty]