English Challenge #3: ALTHOUGH or EVEN THOUGH or DESPITE or HOWEVER

Although and Though
Even Though
Despite and In Spite Of
However
But

OH!! The confusion^^ That is our English Challenge #3 

Many native English speakers will use the following sentences:

1. Although he is fat, he’s very fast.
2. Even though he is fat, he’s very fast.
3. Despite his being fat, he’s very fast.
4. He’s fat; however, he’s very fast.

But one of them is just not quite right. Can you figure out WHICH sentence that might be? And…how can you change the sentence to make it sound more “natural” WITHOUT adding or subtracting any words? You can answer down below OR by visiting my facebook page . Good luck^^