I work in the food industry which I know will be much maligned on here but most of what I see is mostly pretty ethical when it comes to nutrition. I see changing nutrition as a government job not a manufacturer one. Much as the likes of CvT and Tim Spector claim differently there are no secret labs full of food scientists cackling and designing foods to make you eat more. All they're doing (and have time to do) is make foods that are bought and comply with the law. But there is always going to be a natural reinforcement that the foods which are liked more and where marketing works, will be bought more. This reinforces making more of foods which we like, whether they are healthy or not.
But if there's one thing I'd urge you not to eat and not even to shop is the snacks aisles.
I say "snacks aisles" (plural) because this has been a big change since I started work, just how much they have proliferated across the supermarket. My local medium sized store now has:
Cake aisle
Biscuit aisle.
An aisle with crisps on one side and sweets and chocolate on the other
Another separate aisle with more crisps
Other snacks sneaking in elsewhere into chilled displays
When I was young in the 90s there would probably be one aisle of this kind of stuff at best. It has massively grown and if the UPF tag bothers you, it will often contain ingredients which are extracts or would even have formerly been (but hygienically recovered) waste streams like whey powder or some starches.
Reasonably recently the laws on HFSS (high fat sugar salt) got partially delayed then implemented. This is all about where items like this can be merchandised and offers you can have. For example, it used to be aisle end but now can't be.
But what did manufacturers do? Well the obvious thing. They reformulated. They started to promote their products which were already lower in fat etc which then has halo effects on other products in the range. This might not have been an intended consequence but it's an entirely foreseeable one.
To mean that they get around this law, manufacturers do one or more of these things:
Reduce fat, sugar or salt
Adding in fruit, veg, nuts, protein or fibre
What this all means though is that you will see these "slightly better for you" snacks perhaps with more claims or more of a health halo than they had before.
Here's the fact of it all though. None of these are necessary in your diet. Hey, eat them if you want but you do not need to be fooled into changing from "snack x to snack y now with added fibre and 10% less calories!"
Inevitably, these are foods which don't fill you up and I find it so depressing that people buy them. Especially how mindlessly they're eaten in autopilot. The monotonous picking at crisps in front of the TV or glazed look as eating a chocolate bar when driving. Nobody is eating this food with intention and joy. In general people consume it with the same vacant look as a cow chewing the cud. It's also very possible that the nutritional changes make the snacks less satiating so you end up having a little more.
I think that the UPF arguments are hideously overstated. Fact is that most factories making, say a lasagne or a curry are going to use the same kinds of ingredients you use at home. But that's a meal.
It's the snacks that worry me. As a society we did not used to snack as much as we do now. And we certainly did not used to snack on industrially made foods as much as we do. When I was young if I wanted a snack before dinner it was a choice of a granny smith apple (bleurgh) or a "nice" biscuit (which ok, is industrial but is anything but nice). Nowadays we have such an array of stuff around us all the time.
There is a consultation out there right now in the industry that they will tighten the NPM / HFSS rules further. It will make it harder for manufacturers to comply but some will and others will already have the established links between their products in your minds and "not being all that bad for me" as a belief.
So my pitch, from an insider, is don't trade into a "healthier alternative" or something that's "slightly lower in calories". Just ignore this bloody crap and stop buying it. If you want a snack, grab a satsuma or a (nicer) apple.