Can する substitute a previously used verb?


> I want to eat, but **if I do** , I'll get fat.

My attempt at a translation:食べたいけど **それをすると** 太る.

I expect this is totally unnatural. Even if it is okay I fear that adding それを
may make it sound quite formal, but leaving it out just seems totally weird.

Is there a natural way to express this "if I do" part that doesn't repeat the
previous verb? If not, is it natural in Japanese to just repeat the verb? This
would be a bit clumsy in English.




As you suspected, it's best to repeat the verb.

> 食べたいけど食べると太る。

Unlike English that requires you to say "I" twice, Japanese allows you to omit
everything other than the verb itself. IMO the Japanese way is not that
inefficient.

That said, saying それをすると is not bad, either. It sounds a bit stiff, but it's
not unnatural as long as it's said by a mature adult. Note that you cannot
drop それを when the substituted verb is a godan/ichidan verb. You can drop それを
when the original verb is a suru-verb.

Technically, this "do" is a pro-verb (代動詞). Related: [“But when I
do..”](https://japanese.stackexchange.com/q/84597/5010)




As you suspected, it's best to repeat the verb.

> 食べたいけど食べると太る。

Unlike English that requires you to say "I" twice, Japanese allows you to omit
everything other than the verb itself. IMO the Japanese way is not that
inefficient.

That said, saying それをすると is not bad, either. It sounds a bit stiff, but it's
not unnatural as long as it's said by a mature adult. Note that you cannot
drop それを when the substituted verb is a godan/ichidan verb. You can drop それを
when the original verb is a suru-verb.

Technically, this "do" is a pro-verb (代動詞). Related: [“But when I
do..”](https://japanese.stackexchange.com/q/84597/5010)

