Definitely something that's an issue at my house, and something that isn't as well understood medically as it ought to be.

Part of that lies in the definitions.  Medically, hypoglycemia is when you're just about passed out on the floor from low blood sugar.  Someone who is acting like they are going insane because of their dropping blood sugar level is obviously not at that point yet--they still have energy!  I can confirm that they don't feel hungry then, either.

My daughter has something like this going on.  I don't think she's necessarily gifted/2e, but definitely high intensity.  When I googled that term, I came across a couple articles and blog posts that mentioned high intensity kids burn energy quickly and need to eat more frequently.  Also that prioritizing protein and fat over carbs will help keep things level (blood sugar, emotions).  I kind-of knew that my kid needed to eat or she got oppositional and eventually out-of-her-mind ferocious, but having a bunch of people say it helped me to start scheduling regular snacks.  Proactive rather than reactive. 

This also puts me in mind of myself.  Often through the years my husband has come across me in the afternoons where I've been unable to process and coherently respond to his conversation, cranky and getting crankier.  He asks what I've eaten that day, to which I respond, "nothing, I'm not hungry."  After years of this he's begun insisting that I eat something immediately.  And what do you know?  I feel better and can talk rationally again.  Next step is for me to recognize myself when it's happening.