At the moment we're in one of those flux points in our systemic evolution. We have ways to extend the season of the foods we eat (as opposed to eating only foods in season, with a few exceptions) and to extend high-value foods with less valued foods, to preserve and enhance the flavours and appearances of foods, and so much more. We know that evolution generally is a good thing, but it acts over tens to hundreds of generations and is no good to us in our current food crisis.
We can either all eat these foods and take the consequences and let evolution, in a thousand or so years, come up with homo trashophage who can eat anything the laboratories of the world can come up with. Or we can reduce our dependence on those adulterated foods and make careful food choices.
Please note that we also have an economic crisis, which is not over yet, not by a long shot. And which threatens to undermine the things which those unscrupulous food manufacturers rely on, constant economic growth and consumerism. We have a very serious climate crisis which no-one can predict the end result of yet and which may yet destroy much of the food infrastructure we are currently in the first stages of adapting the species to. And indeed, that food infrastructure (land clearing, farming, chemicals to grow the food that then leach into the water table or our bodies, pollution to process and transport that food, refrigerate it, etc) is directly or indirectly responsible for probably 2/3 of the ecosystem, changes which have precipitated this crisis.
So we can choose to continue to damage the Earth, use more and more chemicals and technological means to sustain life on Earth, kill off 90% of the population who will become ecological "also-rans," or we can put a spoke in the wheel of that food machine, go back to basics grown basically, and get that kind of Golden Age come back, only with slightly less rock-like people to enjoy it.
As we really and truly ARE on the cusp of this event, either path is valid.
Put all our faith in technology, and we could end up as I said, able to eat pure chemical nutrients, and technology would insulate us from what will become increasingly hostile weather, remove the need to be responsible stewards of the Earth, and probably eventually lead to lengthy and epic journeys into the Universe to populate other worlds. The catch is that we will of course be adapted mainly to chemical nutrients and artificial environments, and maybe we'll just stay in spaceships and never bother to make landfall. After all, look how readily we take to sitting in front of a computer and interacting via technology.
The alternative is that we dismantle the machineries that have allowed us to live comfortably, and face the fact that responsible living entails personal responsibility and we will have to each of us make hundreds of choices every week, not always eat the most convenient packaged food, and spend a lot more time on our food preparation. On the upside, this does mean that the coming climate shake-up we're in for may not last for as long, and perhaps may not get as severe.
The point is, that both these events are going to happen now no matter what we do, economy and climate events are not going to go away just because we grow a vegetable garden. But whether you have a vegetable garden and good food habits or not may well dictate how well, and how many members of, your family survive... And I'm not trying to sensationalise this, nor do I think I'm being extreme. If experience has taught us one thing, it's that if you're prepared for the worse of two similar scenarios, you're prepared for the less severe as well. If you keep a garden and have local sources of fresh food, you'll be better off even if nothing happens.
Also, don't forget that if you do brave all the additives, people in a few thousand years may well thank you for conferring immunity on them - but it does bugger-all good for you in the here and now...