Joking apart, I think this story line depicts the UK today, the have's and the have not's, especially in the bigger cities like London. I am sure there is a Denise in Manchester, Glasgow and Cardiff.
For someone like Denise who is very proud and will not ask for help, having to go through the bins to pick food out, shows how desperate she is.
How many people use food banks now? The amount of food that gets wasted and thrown away I am not surprised people go through the bins, you could probably get a 3 course meal out of it. It's scandalous the amount we waste.