Human health and nutrition is, of course, highly complex. A substance may be generally healthy in one formulation/concentration, and tend to cause health problems in in another.

A "whole food" is not strictly defined, but is "Group 1" in the Nova food classification you mentioned.

But if they are making this direct link between ultra-processed foods and increased mortality, then surely it's these specific substances that are responsible for it?

Not necessarily. Think about it like cigarettes. The nicotine is what gets you addicted, but it is not what kills you. In a similar vein, these additives might cause you in some way or another to consume an unhealthy diet in the most general sense. So the effect can be more indirect.

I'm pretty sure high fructose corn syrup is banned here and when my wife from the US moved in with me she kept complaining how things don't taste as sweet until she got used to it.

The point of these kinds of efforts is to shift the blame. “It’s easy to know which foods are good and bad with this handy system, so if someone is only eating bad foods, that’s their choice, and the rest of us can blame them for their poor health.”

I'm sick of being told what I should and shouldn't be eating tbh.

Seen plenty of scares over the years about fats, saturated fats, eggs, sugars, carbs, glutens, red meat, meat... Now Ultra Processed Food.

At this point, it's just food. If you're too fat eat less of it. If it's actually dangerous don't sell it.

Aren't there already? Surgeon General's Warning: Do not drive a pregnant woman under the influence blah blah blah

Everything needs warnings because if used incorrectly they will do damage to you in some way. where do warning end?

Do they?

I don't even know what an "ultra processed food" •IS•.

How is it different than the "processed cheese product" that passes for most individually wrapped "American cheese" cheese slices? Or is that ultra processed?

Are Doritos ultra processed or just the regular kind of processed?

Which kind of ground beef qualifies for "ultra"? Only the pink slime or anything that's been chemically treated?

I'm not being a pedantic contrary asshat, I legitimately do not know what qualifies something to be in this category and why it's worse than normal processing.

Bpa from plastic tubing used in the processing of Annie's organic leeched into the food. Is that considered contamination or a side effect of processing?

Will that achieve anything?

Yes! Various countries implement a "traffic light" style health meter that is legally required to be on the front of packaging that also gives a little subtext to say what causes it to be yellow or red (least healthy). So it will say stuff like "excess sodium" or "too much sugar" which actually does work. People don't even realize that some staples are considered UPFs because of preservatives (Tortillas), or are otherwise unhealthy (too much sugar and preservatives in 'health' cereals and yogurts).

This allows people to find staples that do not contain shocking amounts of sugar, preservatives, or highly processed options within the same category. It's worked when implemented well :)

I think it would help. Often times all the items on the shelf look the same with the exception of price.

You add a warning label on one item and the item next to it is $2 more and doesn’t have the warning, I am likely to buy the more expensive item.

Will that achieve anything?

Maybe. Maybe not.

But if we're putting warnings on things and trying to influence behaviour around tobacco and alcohol consumption (don't get me started on drugs) then we might as well do it with foods that can cause serious health problems and are arguably addictive.

I think the best way would be to prevent it from being sold in the first place.

Becoming fat/obese

From my understanding: we extract many micronutrients from food by having bacteria in our digestive tract pre-process the food.

When you eat primarily eat junk food for a long time, the bacteria die of starvation. Once this happens it's hard to get them back and you are crippled by not being able to fully digest healthy food to its full potential.

TL;DR humans need to consume more than just calories and protein

Cancer is a big risk

Had a friend of mine die on Thanksgiving last year in his early 30s from it. He was never obese in his life.

It's a waste of time, the "NOVA" system is subjective and it makes testing it a dead end. Your question will not be answered.

It also doesn't teach nutrition to the people; the core application of it is demonizing food that isn't cooked at home, as if something made in a small home kitchen is magically healthful.

If you want to get a better grasp, here's a nice and short read: (shorter than a book) Series 5: Is the Ultra-processed Food (UPF) concept useful, and for what goals? | TABLE Debates