> The common Nova classification for ultra processing leans heavily on the kinds of processes that happen in factories. [...] I started paying a lot less attention to the entire discussion.

Yes, and that's my point: the Nova UPF label is silly, but you shouldn't let a bad definition get in the way of a good conceptual tool.

"Ultra-processed as any lay person would intuitively understand the concept from the name and a series of examples", and "Ultra-Processed Food as defined by the Nova classification", are two distinct — but not conflicting — concepts. Even if you don't care about the UPF label as Nova defines it, you should still care about whether or not things are "lower-case-u ultra-processed." The Nova definition might be silly, but the concept itself isn't.

If you prefer, I could use a different term, like "highly-processed" or "hyper-processed" here, to distinguish what I'm talking about from the Nova label. But personally, I think it makes sense to actually continue to use the term "ultra-processed", and to just think of Nova as defining the term in a way that overlaps with a useful definition, but which both includes and excludes things that a more-useful and intuitive definition of the term wouldn't. After all, all of Nova's other definitions on the same "spectrum" (unprocessed/minimally-processed, processed ingredients, and processed foods) are perfectly good and useful ones. It makes sense to take that series-of-terms and then extrapolate what moving further in the same direction would take you. And where it lands you is a place that is close to, but not equivalent to, Nova's definition of UPF. Which is the place I'm calling "lower-case-u ultra-processed."

I think it's worth thinking this way, rather than ignoring the Nova classifications altogether, because 1. you still get useful information from knowing that a food is in one of the other Nova categories; and 2. a food being a Nova-labelled UPF still tells you something; and that something may, in combination with what else you know about the food, be enough to tell you that the food is in fact a "lower-case-u ultra-processed" food.

> You're asserting that because food goes bad, it shouldn't be consumed on a regular basis. That just doesn't track, even a little bit.

Because food goes bad quickly, yes. (Or more narrowly, "goes bad quickly for the kind of food it is." But I do think it generalizes across foods, if you're careful about how you compare your apples to your oranges. ;)

Also, it's not a direct correlation. Lability (or its inverse, recalcitrance) is the denominator; but nutrient "load" is the numerator. A thing can be highly nutritively bio-accessible and be fine, if it's not nutrient-dense in the first place. Cucumber is liable but nutrient-sparse, so its high bio-accessibility does nothing to you.

But given two foods with the same density of a given nutrient, the easier your gut and/or bacteria breaks them down (and/or the more they've already been broken down), the more you should avoid them / more rarely you should consume them.

This is the generalization of the logic of "eat oranges, not orange juice", but taken past the trivial point of "because orange juice contains far more oranges than you'd normally eat" to the more interesting point of "even if you drank only the amount of orange juice that was in one orange, it'd still be worse for you than eating one orange, because no amount of chewing is going to break the orange down as thoroughly as a blender or juicer will, and so no orange will ever be digested and absorbed as quickly as orange juice will."

I would note that while many foods go bad (and this can give you a weak intuition about lability), ultra-processed foods would go bad really quickly if not for the chemical stabilizers in them, because all the processing has made them more labile than any whole food has ever naturally been. The ultra-processed versions of these foods would, if not for their stabilizers, go bad far more quickly than the "regular amount of processed" equivalents would.

If you could make Wonderbread with all the same steps the factories do, but just skip the part where they mix in stabilizers, the resulting product would never even make it from the factory to store shelves before going bad; let alone have a useful shelf lifetime. And my point is that knowing that can tell you something very important about the structure of Wonderbread, and about what it will do inside your gut.