#1 says it all!!
#s 3 and 4 are OK, but 1 is best.
1. I am too full to eat more.
2. I am too full to eat leftover food.
3. I am too ful to eat all the food.
4. I am too full to eat all the cooked rice.
5. I am too full to eat the leftover food.
==================
Are they all grammatical? Do we have to use 'rice' or 'cooked rice' here?
2 answers
As for cooked rice, we don't usually eat raw rice, so "cooked" isn't really necessary, but it's fine to use the word.