How do they define ultra processed?

"However, people who eat more ultra-processed foods also tend to "drink more fizzy drinks and less tea and coffee, as well as less vegetables and other foods associated with a healthy dietary pattern," said Duane Mellor, a registered dietitian and senior teaching fellow at Aston Medical School in Birmingham, UK, in an email.
"This could mean that it may not be an effect specifically of the ultra-processed foods themselves, but instead reflect the impact of a lower intake of healthier food," said Mellor, who was not involved in the study."

So like most nutrition studies there correlation but not causation. And they define ultra processed as anything that isn't raw veg or meat. Cool cool cool cool

assjuice: talkyournonsense: "However, people who eat more ultra-processed foods also tend to "drink more fizzy drinks and less tea and coffee, as well as less vegetables and other foods associated with a healthy dietary pattern," said Duane Mellor, a registered dietitian and senior teaching fellow at Aston Medical School in Birmingham, UK, in an email.
"This could mean that it may not be an effect specifically of the ultra-processed foods themselves, but instead reflect the impact of a lower intake of healthier food," said Mellor, who was not involved in the study."

So like most nutrition studies there correlation but not causation. And they define ultra processed as anything that isn't raw veg or meat. Cool cool cool cool

The experiment you imagine you would do to appease the correlation/causation xkcd god would never get past any irb.

I am aware because some of the true valid nutrition studies in science were done in residential schools in Canada by starving indigenous children to death.