As a child in Singapore, it was not possible to skip breakfast because my brain would shrivel up and I would be weak from hunger by 9am if I did not eat something immediately upon waking.
Until age 28, I ate breakfast nearly every day. Through college, the easy availability and social mandate of breakfast made me eat breakfast nearly every day. Working at Google and their absurd free meal program meant eating breakfast every work day. (A cunning and effective scheme by People Operations to make high-value workers come in early and leave late.) Even at Anderson Ranch, staff got breakfast because we opened up the workshops before 7am each day.
Returning to school was the beginning of the change. An employment situation—if a PhD program can be called that—in which I no longer went to an office at a determinate time meant that initially I went to an extreme of going to bed at 3am and waking up close to lunchtime on days when I had no morning seminars. I soon noticed that it was easier on those days to think or read in the early afternoons. I chalked it down to additional sleep. Then, on days when I did have to get up for morning seminars, I stopped eating breakfast because I would have to make it myself and that was more trouble than I wanted to go to. After a few months, I realised I could think and read with more facility when I skipped breakfast than when I ate breakfast on the weekends. (This is of vital important if you’re reading classical sociological theory in the hour before discussing it in seminar.)
It’s hard to have a detailed awareness of your current physiological, cognitive, and affective state, even harder to be aware of whether and how it is changing, harder yet to have good ideas of causality. Somatic awareness takes great discipline (I wrote here about how a regular practice aids in this) or discontinuity. If the effect is pronounced (reading almost twice as much turgid, poorly translated German) and the change associated with it fairly abrupt (not eating breakfast on seminar days) maybe you have a chance of recognizing your state, how it has changed, and what caused it.
The importance of breakfast appears to be a social construct in a society where we do not leap out of bed before daylight to hew wood and carry water. (However, it is possible to go for a run in the morning without eating breakfast either before or after without keeling over.) In fact, these days, if I can help it, I don’t eat until 1 or 2pm, and not after 7 or 8pm—so-called intermittent daily fasting. In my n=1 experience from two years mostly on this schedule, skipping breakfast and starting to eat late in the day does not seem to lead to brain dysfunction. I am neither wasting away nor starving by noon. In fact, both cognition and mood seem improved.
Give it a shot.