To say "I'm hungry" in Japanese use the following phrase -
o - naka ga suita
Naka is a generic word for things in the middle. The kanji for naka is very simple - 中. It looks like a box with a line drawn through it.
o - naka 織中 おなか - stomach, belly, midsection, torso, etc. Literally, "the honorific middle".
Here are some uses of o-naka -
1. o - naka ga suita - I'm hungry
2. o - naka ga itai - I have a stomach ache.
3. o - naka no ko - The expected child.
織中 の 子