I think it'd be really nice if the Nutrition effect gave you hunger saturation as well as just the hunger points, that way you can be at full hunger at all times while under the effects of the beacon and it doesn't occasionally go down just by running etc. Just a little thing but I think it would be a lot nicer. Cheers for the high quality mod anyway!

The reason for Nutrition not providing saturation is Minecraft's hunger system utilizes saturation for rapid health regeneration, and I found it to be too powerful and made Regeneration feel pointless. However, hunger going noticeably below full sounds like a bug. Are you using any mods that would cause hunger to deplete faster than normal?

It's not that it goes way below full, just that it occasionally goes down by one which irks me as I feel like it should stay at full all the time while you're under the effect. Not a huge issue and your explanation as to why you didn't do that in the first place makes more sense now. It'd be good if there was a way to just pause hunger consumption while under the effect, as I think that would solve the issue as well, but I don't know how hard that would be to implement or if it's even possible.