There are several issues that contribute to this situation. Not only people on UC but people on zero hour contracts, and others on very low wages. Some people have to choose between eating and heating, and this is the case in many young people as well as older people. Food banks can only provide so much food for people who qualify. You have to have a referral for it, and are given limited amounts of food per visit. There will always be people who are better at budgeting than others, but even so, with the best will in the world if you have little or not much food in the cupboard you are obviously going to struggle and and get into difficulties.
I have also seen various TV programmes (ie) Jamie Oliver in a town in Yorkshire trying to show people how to cook healthily and cheaply instead of living of takeaways, and also read Jack Monroe's book from our library, in which she documents her struggle and how she came up with the recipes she did to simply survive.
Someone above has mentioned a school in Morecambe, well two schools there also provide laundry facilities for some of the parents who are desperately struggling, to allow them to bring their children's uniforms in and wash them, as they have not the money to top up their pre- payment meters and wash them at home.
I was born and brought up in the north and we knew a lot of poverty, even though our parents were taught to cook basics there was not always the money for the ingredients and had to be very inventive and creative to put meals on the table. We had gas meters and electric meters - one took shillings the other pennies. I can remember then, some neighbours lending each other small amounts of money to put in the meters and giving it back on payday. Lending cups of sugar etc was not unheard of then either. I think it is a lot harder these days because living standards as such have risen over the generations, also not so much community spirit as back then when people did seem to be more neighbourly and help each other out.