Surely tinned and dried foods have provided better nutrition, to those with less money in urbanised countries and this is a very good thing?
Neither of these things qualify as Ultra Processed (even if some tinned food can do). The basis of the argument against UPF is that it isn't bringing better nutrition, but that it's associated with range of serious health issues, linked to diet, including malnutrition.
At the extremes, there are several metadata studies that suggest UPFs are probably more addictive and harmful than alcohol or drugs.
It's a interesting topic, and off topic, but to give a simple and simplified example, UPFs use artificial emulsifiers instead of eggs to bring particular characteristics to food. This is much easier for a food manufacturer to deal with.Artificial emulsifiers are easier to "manufacture", transport, don't go off and have consistent qualities. But, don't bring any nutritional value to the food.
Another valuable thing about artificial emulsifiers is that you have more control over the texture of food, and texture is a key trigger in making us want to to keep on eating something. And there are strong links between UPFs, overeating and obesity.
These are very simplified examples just to give a feel for the issue, and as with everything, it's a complex issue. I'm still weighing up the evidence, but it doesn't seem something we can afford to just ignore.
I cut out UPFs 10 months ago, I'm now eating things that I used to avoid because of lifetime of dieting e.g. lots of nuts, various minor health ailments have cleared up, and my yo-yoing weight has stabilised at 5kg less than the lowest weight I have been in the last 30-40 (maybe more) years.
Things I've noticed are, for example, I've lost the constant craving for food that I used to have and by buying biscuits without UPF ingredients, I no longer have to fight off a desire to eat the whole packet., I feel I've had enough after one or two biscuits. To be fair these biscuits are also much more expensive, but they also last a lot longer.
And to bring this back to the photographic point I was making, the thing about UPF is that its engineered to trigger all the physiological levers that make you want to eat more, And they have hgh fat levels with very low nutritional levels.
Similar psychological triggers have been shown we are drawn to bright super saturated images, and I was suggesting that given people's millisecond attention span, they trigger a like, and people have moved on before realising how awful they are.
Studies have shown that given a choice, people prefer eating foods with UPF, because they have high levels of the physical characteristics we like in our mouth.