"Ultra-processed food" is the new term for "junk food" for people who thought it needed three more syllables.
They're both vague you-know-what-I-mean terms, and don't have any place in research papers, which really ought to be asking more specific questions. Are ultra-processed foods bad for you? You might as well ask whether "yucky foods" are good for you, or what the health effects of "appetizers" are.
If you want to know if white bread or artificial colors or emulsifiers are unhealthy, ask that question directly instead of using this vague proxy category.
I am aware of the Nova classification. "Vague" was the wrong word for me to use. "Overly broad" is probably closer to what I mean. Just read Group 4's definition. If "ultra-processed" can mean a million different things, then it doesn't matter that you've precisely defined all the things it can mean, your study will still be conflating a million independent variables.
If you think emulsifiers are unhealthy, conduct a study on emulsifiers. If you think the absence of Nova group 1 foods is unhealthy, study that. I am questioning the value of studying foods with emulsifiers OR no group 1 ingredients OR added sugar OR were extruded OR were moulded OR which have "sophisticated packaging" OR have fruit juice concentrates OR hydrogenated oils OR etc. etc. etc., as if they formed a single scientifically meaningful group.
They're both vague you-know-what-I-mean terms, and don't have any place in research papers, which really ought to be asking more specific questions. Are ultra-processed foods bad for you? You might as well ask whether "yucky foods" are good for you, or what the health effects of "appetizers" are.
If you want to know if white bread or artificial colors or emulsifiers are unhealthy, ask that question directly instead of using this vague proxy category.