How do you say you're fat in Japanese?

Answer 1

'You are very fat now' in Japanese may be translated as 今の君がすごく太ってる (ima no kimi ga sugoku futotteru). I think a gentler way of saying this would be最近君がちょっと太ってきたね (saikin kimi ga chotto futotte kita ne) which would literally mean "you've put on a bit of weight recently, huh?" in Japanese.

Answer 2

I hope that you're not going to use this to insult someone!

It is either
あなたの脂肪があります。

or

私は脂肪です。

depending on who you are referring to.

Answer 3

太い or futoi