An ESL student produced the following sentence:
“The Western diet seems to be more unhealthy than the Japanese one.”
The use of “one” immediately struck me as awkward, but not necessarily incorrect, as diet can be both countable and uncountable depending on the situation.
I corrected the sentence to, “The Western diet seems to be more unhealthy than that of Japan,” to avoid any confusion, but I honestly couldn’t decide if her version was actually grammatically incorrect or merely grossly awkward.
When using a strictly uncountable noun to make a similar sentence, such as, “The Western furniture was less stylish than the Japanese one,” it’s obvious that it’s incorrect.
However, when switching back to a noun that is both C and U, such as in, “The Western environment is less polluted than the Japanese one,” it becomes ambiguous again (to me anyway).
I realize that the best solution is to just fix the sentence as I did in the first example, but again, what I want to find an answer to is whether what she initially wrote is grammatically correct or not.