For a Chinese learner, I think right now you don't have to remember so many things. Although Fransico's answer are very good indeed, focuses on the origin of 东西 东西 in Chinese likes もの in Japanese. 吃的东西=something to eat=食べ物 (but in daily life we say use 东西 to mean something to eat directly) 阅读的东西（材料）=something to read=読み物 also...笨蛋东西/混蛋(混账)东西=fool=ばがもの (Okay...don't tell other people is me who told you that...) And if you say 你是什么东西 to somebody, that means you are angry at him/her, just like "Who do you think you are?" You look down on him/her. But don't use that unless he/she really did something evil to you. The two sentences you wrote are both correct. No doubt about it. But the second one. 你喜欢吃东西吗？ We don't ask people like that VERY often...if you ask somebody what does he/she like to eat it would be better and natural. That is 你喜欢吃什么东西？(What do you like to eat?)

吃东西

你今天吃了什麼東西? 你喜歡吃東西嗎? the two expressions are correct. simply,"东西"has three meaninngs.1.direction.东西南北。2.things,almost all the things can said"东西"，animals,materials,foods,etc. like these words"what's this?"u can translate as "这是什么？"or "这是什么东西？"3.sometimes used to swear. eg."**真不是个东西！"or"**什么东西呀！" there is funny thing when sometimes kidding between friends. ...... A:......我当然知道你是人，你不是 东西（things） B:你这家伙，你才不是东西呢（here is scaring，means u bad man） A:好好好，你是东西.(means u good) B:气死我了，我不是东西,我是人。（here,B meant "things",but all know it also means he is a bad man,then A's aim come true）

有两种发音方式来表达“东西”，不同的发音代表不同的意思。there is tow different inflections of"东西"，different inflections has four different meanings. 一、东西 dōngxī 1、表示方向：东面和西面 例：日本在中国的东面。 1、direction：[east&west] EX:Japan lies to the east of China. 2、表示距离：从东到西的距离。例：东西相距5500公里。 2、distance:[from east to west] EX:The distance from east to west is over 5,500 kilometres. 二、东西 dōngxi 1、泛指各种具体或抽象的事物 例：吃东西、写东西 1、things EX:eat something、write someting. 2、特指人或动物(常含喜爱或厌恶的情感) 例：可爱的小东西（喜爱的）。 2、people and animal[includes affective] EX:cute little thing（lovely）。

东西可以用来指食物 东西这个词的来源现在尚未定论