"I thought that I wasn't hungry, but look, I finished all of it."
"Yo creía que no
tenía hambre, pero ¡mira!, terminé todo" (Rusty's)
"I didn't think that I was hungry, but look, I finished all of it"
"Yo no
pensaba que tuviera/tuviesehambre, pero ¡mira!, terminé todo"
I usually use "pensaba" instead of "creía" (both are OK) in this kind of sentence, because "pensar" has a less-deeper meaning.
little children says "me lo comí todo"
Saludos