[callmeal]

>a factory-made carrot cake is labeled UPF, but a home-baked one isn't, even though they're practically the same thing).

Actually they are not. "Practically" is carrying a lot of weight there. The factory baked cake will have a lot more extraneous ingredients and usually has a larger quantity of sugar and fat. Similar to how restaurant food generally has a lot more salt and fat than home cooked food.

[macNchz]

Yes, right off the bat a factory made carrot cake will very likely contain dough conditioners, colors, and preservatives that no home cook would put in their scratch made version.

The direct impact of those extra ingredients alone or in combination is not entirely clear at this point, aside from building evidence that people whose diets include more of that seem to be less healthy.

[DennisP]

Yep just a glance at the ingredients shows obvious differences. Other issues I've seen studies about include contaminants from conveyor belts, and for many snack foods, processing into smaller particles, effectively making them partially pre-digested.