too many, too much和much too这三个词语的主要区别在于它们的中心词以及它们所修饰的词不同。三者之中的前一个词都是修饰词，用来加强语气，后一个词是中心词。因此，在使用时只需要考虑后一个词的用法就行了。分述如下:

1. too many的中心词是many, 用法与many相同，用来修饰复数可数名词。例如:

He's got too many questions to ask you. 他有很多问题要问你。

They bought too many eggs yesterday. 昨天他们买了太多的鸡蛋。

2. too much的中心词是much, 用法与much相同，用来修饰不可数名词。例如:

We both have too much work to do. 我们俩都有很多工作要做。

She spent too much money on clothes. 她花太多钱买衣服。

The teacher told him not to spend too much time playing games.

老师叫他不要花太多时间玩游戏。

I'm afraid that I've given you too much trouble. 恐怕我太麻烦你了。

另外， too much还可作名词性短语，用作宾语; 也可作副词性短语，在句中用作状语，修饰动词。例如:

You've given me too much. 你给我的太多了。

I have too much to do every day, so I am very busy.

我每天都有很多事情要做，所以我很忙。

He talked too much at the meeting, didn't he? 他在会上讲得太多了，是吗?

Don't eat too much. 不要吃得太多。

3. much too的中心词是too, 用法与too相同，用来修饰原级形容词或副词。例如:

You're walking much too fast. Slow down. 你走得太快了, 慢点。

I'm afraid that this cap is much too big for me. 这顶帽子我戴恐怕太大了。

It's much too cold outside. You'd better put on your overcoat.

外面太冷了, 你最好把大衣穿上。

根据该题句意“他吃了太多的事物，因此他很胖”可知，该题正确答案为D项。