The food supply will not increase nearly enough to match this.

nearly enough to do this为副词词组，修饰不及物动词increase.

其中enough是中心词，nearly和to do this都是修饰enough的。传统语法把二者都叫作修饰enough的状语，否成副词短语，然后副词短语修饰谓语动词。

现代语法则认为to do this是enough这个副词的补足语，nearly为词组层面的次修饰性状语（下加状语subjunct ).

enough to do sth 中，enough是中心词，不定式修饰enough，而不是enough修饰不定式。所以这是一个副词短语，而不是不定式短语。

enough to do sth 或 enough for sth 是一种固定修饰关系，即enough可以被不定式或for介词短语修饰，构成副词词组。该副词词组可以修饰动词、形容词或副词。例如：

He is not clever enough to understand this. 划线部分修饰clever。

He ran quickly enough to catch up with us. 划线部分修饰quickly。

The food supply will not increase nearly enough to match this. 划线部分修饰increase.

He has enough money to buy the whole city. 不定式为enough的补足语。enough为限定词（传统语法认为是形容词）。

He has money enough to buy the whole city. enough在此为形容词，划线部分修饰money。