re food manufacturers, i do think we live in to extent an "obesogenic" environment in the UK. that's not purely the fault of the food manufacturers, but they have their part to play in it, as do shops, our traditions etc
the fact is that we are animals, we have evolved to seek out food to sustain us, particularly through the winter months when food is scarce in the natural environment. we are particularly attracted to sweet-tasting foods, as they tend not to be poisonous, which also tended to only be available at harvest time (fruits), so we could gorge ourselves and store up energy for the winter. also fatty foods which help us feel full and satiated.
of course, these foods are now not only available all year round, they're also available 24/7 in our society. we have evolved to experience positive responses to eating (in order to survive), so it's not surprising that when food is available we will want to eat it, and we will be most attracted to the food that makes our pleasure receptors go "ding ding ding ding ding"!
food manufacturers want to be profitable companies, so will naturally develop the foods that most people most want to eat. that is normal in a capitalist society
if shops can make more money by being open 24/7 then they will, again, not surprising
add to that the way that we are wedded to food in a social way - sharing, celebrating, comforting, being hospitable - food as social currency. it can be very difficult to get away from this, people don't want to be social bores who don't join in
of course some people (no doubt many who have commented on this thread) will have less attraction to food, or more willpower, or live somewhere or in a way that is less convenient in terms of access to food. but for many it's a constant battle because there is so much food, and it's always bloody there and always easily and reasonably cheaply available, it's not illegal, it doesn't stop you being able to drive or look after dependents. add people with mental health or emotional problems that are either associated with or have an impact on eating behaviours to that and it's not surprising really that so many people struggle. in some ways it's surprising that the obesity rate isn't higher!
i don't have the answers, and i'm not about to say that we should have a blanket ban on processed food or 24hr supermarkets etc. i'm just trying to say that it's not as easy as many people believe