Another Aussie here just to give me interpretation of the way it would be translated into English
我饿了
This is more likely to be used as a interjection or to emphasise a point rather then a response eg. you want to indicate your hungry to someone as a new topic
我要吃东西因为我饿了 (I want something to eat because I've been hungry for a while now)
A more aussie way of saying the above would be "come on mate/love I'm hungry let go get something to eat" but what is expressed as apart of 我饿了 isn't really used in the Australian English language
There are time when you can use it as a response though eg.
Q: 为什么你要吃
A: 因为我肚子饿了
However 因为我很饿 also works in this situation
我很饿
This is used more as a building block rather then a stand alone statement, I would personally only use it during a conversation and not as a stand alone statement eg.
女朋友:你饿吗
我: 我很饿
女朋友:你要不要吃米粥
我: 要吃谢谢
It took me a very long to understand and learn to use 了 because as previously mention it would literately translate into "already" and in most cases as it's not used in this context in Australia as if I said "I'm hungry already!" to one of my friends the response would be something along the lines of "Oh my are you okay princess, please, please don't get up; just wait there I will go make you some fairy bread"
Something to keep in mind 我饿了 isn't always to complain about hunger it's just a way of expressing it.
了
withalready
.