Comment by WuxiFingerHold

Damn, thanks for your insights. I recently discovered how much better I sleep when fasting. During my fasts I'm taking precise amounts of electrolytes (sodium, magnesium, potassium: https://en.wikipedia.org/wiki/Oral_rehydration_therapy). Being off my fasts I'm getting sloppy with my electrolytes intake and here we are: I'm getting the same symptoms you describe. Not severely, but noticeably.

Now I need to find a proper supplement in Germany. Most electrolytes that also have the recommended amounts of glucose contain artificial sweetener which is a big no-go for daily usage for me.