Oooo, this sounds very familiar. I was like that for years. It was always particularly bad if I was out from home and forgot to eat. I would get very irritable and my head would start spinning. Eating would remedy it very quickly although I would be left feeling a bit odd for a few hours after getting very hungry.
I have PCOS (this is relevant - keep reading!), diagnosed years ago before much was known about the condition and it was thought of as a pure gynae issue and the interraction with other hormones (including insulin) was not well known. A friend mentioned she was on a PCOS diet and recommended the book she got it from to me. The book is about the condition in general and I read about the symptoms you described and learnt that they indicate insulin resistance. I had no idea it had a name or that it wasn't normal - it was normal for me! I now eat a low(ish) GI diet and feel hungry in my stomach rather than my head. It was a revelation. I had no idea that hunger was supposed to feel like that.
Although mine is linked to PCOS, men can be affected by insulin resistance too. Your husband should try eating lower GI food and cutting down on refined sugar. Not only will he feel better, but insulin resistance is often a precursor to type II diabetes so he should do his best to get it under control. Basically the pancreas overworks to pump out lots of insulin when he eats something sugary which sends his blood sugar too low, he gets hungry and grumpy, eats something sugary or with refined carbs and the whole cycle starts again with his pancreas working overtime.
PS - I bet he loves carbs, right?