YOU SAID:

I didn't under stand the full extent of his girth at first

INTO JAPANESE

私は最初、彼の胴回りの全容を理解していませんでした

BACK INTO ENGLISH

I didn't understand the whole picture of his waistline at first

INTO JAPANESE

最初は彼のウエストラインの全体像がわかりませんでした

BACK INTO ENGLISH

At first I didn't get the big picture of his waistline

INTO JAPANESE

最初は彼のウエストラインの全体像がわかりませんでした

BACK INTO ENGLISH

At first I didn't get the big picture of his waistline