I personally find that my BG gradually gets higher the longer I go without food. I think my body panics if I've not eaten for a while, fearing that I might somehow starve to death, so my liver pumps out more glucose to keep me fueled up.
I think this is one of those phenomena that varies very much with individuals, others might well drop BG without eating and some who intermittently fast seem to be quite stable on it. But it sounds like you might be like me in this regard.
I was always advised that steady pacing of eating - and not missing meals - was better for more consistent and stable BGs and have personally found that to be true, for me. I simply feel rough if I go hungry for long.
Plus, if you have a breakfast that's predominantly carb, it can cause a pretty quick release of energy that is soon depleted and leaving you hungry sooner than if you'd had a slow release breakfast like bacon and eggs. Although shredded wheat would be better than white bread toast or cornflakes, as such, as it takes a bit longer to digest.
I've always felt that carbs based meals provide quite transient and short-lived energy, After a richer, more fat-loaded 'cooked' breakfast you might find that your BG didn't rise as much without lunch, as your body would have a steadier stream of slowly processed resources available from breakfast - it would keep you going for longer.
