If I've fasted since an early evening meal and I skip breakfast (and I've done it for a week or two) I'm razor sharp until I eat.

My mind feels significantly keener.

In fact I used to dread eating something, anticipating what felt like a loss of 15 IQ points

I do the opposite. I do not eat breakfast and I'm completely fine. Dinner is around 6 p.m. so I go about 18 hours without food every day.

I only have coffee in the morning and the only calories in that come from a bit of milk I take in it.

I don't necessarily feel hungry at lunch time either. If there's something going on at work (prod issue, in the zone) I might find myself at 2 p.m. without having eaten.

Sometimes on the weekends I will have a leftover pancake w/ jam for breakfast. What I noticed is that if I've had that, I usually crave food again at noon.

There is unexplained difference regarding body energy usage if one eats most calories before noon or in the evening. With the former body spends like 100-200 more calories than with the latter. This is independent of sleeping patterns, what one eats and what one is doing. Even if one works night shifts, the same pattern persists. And it is not clear where exactly the extra energy is spent.

Wait, so about that night shift.. you mean “before noon” isn’t a relative reference to a period of time after waking, it’s an absolute reference to time of day regardless of when sleep takes place? That’s interesting.. irrespective of latitude (sunlight hours)?

Yes, this is in reference to absolute time as measured by highest point of Sun. The effect is so puzzling that there were plans to see if it exists in polar regions during winter time the last time I read about it.