Meals that you only need to heat in a pot/oven and that are stuffed with preservatives and other stuff.
Some people include more in that "processed food" category, some less, but practically everyone agrees that preparing meals yourself using raw ingredients is a good idea.
The point is salting that soup and frying the chicken yourself, which avoids a lot of substances with often still uncertain long-term effects or potentially harmful effects on the environment.
Of course it's more a rule of thumb, I thought that goes without saying.
Meals that you only need to heat in a pot/oven and that are stuffed with preservatives and other stuff. Some people include more in that "processed food" category, some less, but practically everyone agrees that preparing meals yourself using raw ingredients is a good idea.