Depends on the intensity. I do ~60 mile Z2 rides quite often, and for those I don't eat anything. Not breakfast beforehand and nothing during the ride. I've done hammerfest of about that length on an empty stomach too and never ran into any issue, but I rather have some food with me just in case. If the distance increases and there is going to be some intensity then I'll bring some food, but even then we're talking a banana, some nuts, and maybe an energy bar. Different people have different requirements though, so just do what is best for you. Eating every 30 minutes sounds insane to me, but if that is what you need then that is what you need.