In the sentence 'They often go to Italy because they love the food', 'They often go to Italy' is the main clause and 'because they love the food' is a subordinate clause.

在They often go to Italy because they love the food这个句子里，They often go to Italy是主句，because they love the food是从句。

《牛津词典》

The main clause talks about the likely result.

主句谈论可能的结果。

youdao

Clauses of contrast give information that surprises, or contrasts with the main clause.

对比状语从句用来表示超出主句表达的意义或与主句形成对比的信息。

youdao

He agreed with the four conservatives that the law violated the Commerce Clause of the Constitution, which was the main claim of the 26 states that sued.

WSJ: Toodle-oo to 2012