The "free marketeers" like to present the food we eat as a free choice issue. Label it up and then sell it and people can choose. However I think this is extremeley misleading. Obesity and ill health (Type 2 diabetes for instance) is now costing the NHS £6bn per year and this is expected to reach £10bn by 2050.
Food manufacturers are the new cigarette companies, funding scientists to produce misleading papers blaming everyone but themselves for loading food full of Sugar, transfatty acids, corn starch etc. High Fat, nutrient poor foods that are shortening peoples lives and filling up (extra large) beds in hospitals. Farmers have lobbied governments (in Europe and America) and are hugely funded by public subsidy. It is a choice whether we subsidise farmers to produce quality products and manage our rural environment (as has largely been the case in Europe more recently) or subside them to mass produce cheap food with little regard to quality or the environment (as has been the case in the US - but not in every state).
What I believe is that food manufacturers - especially the huge multinationals - do not pay the social cost of the crap they sell - blaming it on consumer choice - whilst all the time blocking clearer labelling, advertising restrictions ~(junk food during kids programming)etc.
In years to come I think we will look back to now and regard some food companies the same way we now look back on cigarette companies, who knowlingly sold cancer causing cigarettes to people whilst doing all they could to hide the true impact of the damage they were doing.
There is a role for government in what people eat. It is not the nanny state as in the end it costs the tax payer when they end up ill. How we do this is not straightforward but everyone needs to bear in mind that the food complanies, farmers and biotech firms (Monsanto etc.) have HUGE lobbying machines in the EU and in the USA, and will fight tooth and nail to protect their profits - public health is not in their interest. Ask yourself why they lobby government??? Why do they need to lobby government if they are doing something that the "free market" needs. POST brexit these lobby firms will be at Westminster and I do not trust Liam Fox to stand up to them. He will trouser as much cash as he can (remember he stole more cash from the taxpayer than anyone else in the MP expenses scandal) and will then end up on the board of all these companies after he leaves parliament - like all these othere politicians.
A FTA between the US and the UK is a huge mismatch in power and I worry that the we will take anything we are offered. We must be super cautious - but I fear the worst. That is why TTIP took years and years to negotitate. Chlorine washed Chicken and Hormone injected beef are just small examples of what corporate america has in store for us. And it is the poor that will suffer (not in the pocket but in health) - as well as, in this case UK farmers and the rural economy - not the well off that can afford the better options. But remember in the end it is the taxpayer that will pay - and the corporations that trouser the profits.

What is your evidence for that? That is, other than a few cases of problems with some towns or neighborhoods where the local ordinances about property upkeep are strict or misinterpreted, or the issue is growing food in an inner city to sell it. That would never happen back in Britain...

Given the amount of land, I'd say it is far more common here to grow or hunt for food.

I saw an interview with a woman who was told by her doctor that she had Diabetes and she must change her diet and eat more fresh produce. She went out to buy fresh fruit and veg but there was not one shop that sold anything fresh.

The egg came before the chicken. What did dinosaurs hatch from?