I ate it
You add this to a story to make it even more ridiculous. Like someone ate a whole bowl because the food was that good.
My friend said he ate a whole bowl of soup. I said 'I ate it.' He said 'You ate a whole bowl of soup?'
My mom said she ate a whole pizza. I said 'I ate it.' She said 'You ate a whole pizza?'
My brother said he ate a whole cake. I said 'I ate it.' He said 'You ate a whole cake?'