YOU SAID:
I had pizza for lunch.
INTO JAPANESE
ランチにピザを食べた。
BACK INTO ENGLISH
For lunch I ate pizza.
INTO JAPANESE
ランチにピザが食べた
BACK INTO ENGLISH
Eat pizza for lunch
INTO JAPANESE
昼食にピザを食べる
BACK INTO ENGLISH
Eat pizza for lunch
That didn't even make that much sense in English.