I'm increasingly noticing that if I eat something with wheat, just by itself, I feel a bit spacey for the rest of the day. I seem to be able to eat it in the context of a fuller meal, so long as it's not much.
I've also noticed for a long time that sugar makes me feel a bit foggy and out of it, and seems to - not sure about this bit, but think it probably does - deepen my mood if I'm feeling a bit low already.
I normally try to eat pretty healthily, so I think that I'm becoming more sensitive when I go off track.
What have you noticed?