I’d look into the feeders. They’re $60 here & you set how much food is served & how often. They work with pellets or flakes.
Just because something can survive without food doesn’t make it natural or right.
Fasting for a day every so often for therapeutic reasons isn’t the same as for a week for convenience.
I’m beginning to agree with
@taxidermynerd : maybe it’s time people stopped selling fish.
No one would think it’s okay to not feed any other creature for a week. They’d survive too & some might even have a few pounds to shed. We’d survive too, but I don’t recommend it.