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

The main clause and subordinate clause of compound sentence must have subject and predicate as same as the simple sentence.

复合句的主句和从句也和简单句一样，必须有主语和谓语。

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

By one clause or another, all critical discussion of the main issues facing the country, such as the peace process with Israel or the position of Islam in society, is in effect outlawed.

ECONOMIST: Jordan