Adverb Clause of Proportion

Adverb clause of proportion or proportion clause shows the result of an action in relation to another action.
The most important subordinating conjunctions in this category are "as" and "the . . . the". For example,

• As I listened to him speak, I slowly came to like him.

(At first I didn’t like him, but my opinion of him improved in proportion to the time I spent listening to him speak.)
The same effect is possible with the the... the :

• The more I listened to him, the more I liked him

Here is another example using the same construction

• The fatter I get, the more I want to eat.

Notice that in these examples a comparative adjective appears in both clauses of
each sentence. "The...the" can only be used when two such adjectives are present.