Dende tells Kuririn (Krillin) and Gohan on Namek that the Nameks don't eat, they just need water. But when the past was told earlier about Kamisama and how he grew up in the middle of nowhere, in the flash back he is shown eating a fish.
I never noticed that before, I'll have to check it some time. But there is another time in the series that contradicts what Dende says, in the Japanese episode 125 Chichi is yelling at Gokou about not having a driver's license, Gokou drags Piccolo in to the argument and Chichi threatens both Piccolo and Gokou by saying that she won't cook for either of them if they don't get a license, this apparently worries Piccolo and both of them agree, but Piccolo shouldn't be worried nor should he care care if Chichi doesn't cook for him since he doesn't need to eat. I'd like to note that this is a subtitled version and might not be completely accurate but look for yourself at this address: http://www.planetnamek.com/movies3.html (it's the 6th movie clip of the Android Saga section) again it is subtitled and might not be accurate.
And also, when Gohan, Krillin and Bulma arrive on Namek, the two Nameks (forgot their names) are eating as well. However, it may be possible that Nameks don't need to eat but they do it for the pleasure. And doesn't anyone find it strange that even though Piccolo and Kami lost their memories when they arrived on earth, they could speak the Namek language perfectly?
Hugo, you know how FUNimation royally f*cks up American DBZ. Maybe Chi Chi didn't really say anything about cooking. We'll just wait and see if they'll release a subtitled Japanese DVD of that episode. I got The History of Trunks on DVD, and there are one or two lines of dialogue in the whole thing that aren't changed between the English uncut and the Japanese version.
there is also a time in dbz (between the freiza and android saga) where goku catches a big fish and brings it back and piccolo says "oh no not fish again" but why should he care if he doesnt eat.