～というのは (〜to iu no wa)

Nihon ni iku to iu no wa, Nihon ni ryokou suru koto desu.

Going to Japan, that is to say, traveling to Japan.

Kono mondai wa muzukashii to iu no wa, kaiketsu ni jikan ga kakaru to iu koto desu.

When I say this problem is difficult, I mean it takes time to solve.

Kare ga okotteiru to iu no wa, kare ga fuman wo kanjiteiru to iu koto desu.

By saying that he's angry, I mean he's feeling dissatisfied.

Futoru to iu no wa, taijuu ga fueru to iu koto desu.

Gaining weight, that is to say, increasing one's body weight.