The whole UFP thing is so wishy washy. It’s such a broad category it is essentially meaningless, one of the earlier guardian articles talked about sliced bread being a UPF as it has added vitamins and minerals due to law.
If you closer at the whole topic it just comes across as saying if you are poor and eat food that you can afford you will die earlier. Writing a reminder of this on the food will not help anyone but it will make poor people feel a bit more like shit.