Depending on that example, there are many ways to reach that. The most common ones are:
a) The food is objectively not enough (e.g. you invited ten people over and you bought enough food for 5 people)
b) You might know the people that are coming over and you know that the current amount of food is not going to cut it.
c) You know the person that bought the food is tight with money, so they did their usual “magic”
a and b are more an assessment based on known/obvious facts/data.
c is what I’d call a judgement.
Sure. Here it is:
I could have left it at that and made that point “by demonstration”. 
If you want easier examples, there are questions that have been predetermined by experience or your character, for example:
– Do you like spiders? No. (Almost all of them are harmless here, but you can have a phobia. You do not need to assess, or judge the “next spider” in line. You already know what’s up)
– Do you enjoy watching football? Yes or no, you already know the answer. You’ve tried the activity and you either like it or not. After that, it is now just a statement of fact and no longer a matter of judgement. If you watch a particular game and it is boring you can judge that “damn this game was a bland soup”, but that probably wouldn’t change your general disposition towards the activity overall.
– Is it hot? Yes or no, there are objective indicators for that kind of thing (thermometers)
and so forth…
This post might interest you, then, since it seems to answer - or at least adress - that issue:
What non-Go book are you reading right now? - #133 by JethOrensin