Int food does not increase MATK directly, but transitively from receiving INT.
Items, that increase MATK directly (I know about, see all here)
- Box of Drownsiness (20)
- Durian (10)
- Rune Strawberry Cake (5)
Screw links to RMS which can't be posted as hrefs :/
Just search for items with script sc_start SC_MATKPOTION
