I remember this phrase from my study of German years ago, and it really made an impression... it was contrasted to the alternative (but considered vulgar) Ich bin voll...
Until recently I had forgotten about these phrases and their distinction, especially as I didn't really understand the difference, and filed away the distinction as just polite rather than technical.
I now completely understand the difference.
The short story is that I found myself living in an ever-tightening cycle of eating, and needing to eat. I would wake up hungry, eat, run or bike, eat again, go to work and endure an irritable itchiness that could only be satisfied with a sugary snack, eat a 'healthful' large lunch, snack again, and be starving again by dinnertime.
This continued for years, until the cycle tightened to me waking up twice a night to either eat, or drink, something and sleep again, or stay awake and suffer from fidgety dissatisfaction.
After eating, I could count on a one or two hours of focus and concentration, but that yielded to irritability if I couldn't quickly get a cookie, rice-ball, can of cold beer or hot cocoa. Exhausting.
For the last eight weeks, I have eaten nothing but meats, fats, and vegetables, completely avoiding sugars, carbs and grains. Within 4 days I was in ketosis, and I haven't faltered, or been tempted to falter, yet.
Ich bin satt..
Since then, after my meals of eggs, beef or pork and some veggies sauteed in butter or coconut oil, a sense of well-being... satiety,... washes over me. I can think. I can concentrate. Not only don't I crave snacks, I can skip meals without even noticing. When I am 'satisfied', I am done eating.
Actual differences that I should have recorded are many, but I entered into this as a trial, not really a test, so I didn't record or measure hard data. What I can report though, are these:
1) My body temperature is spot-on 36.6 deg now. It has always been a full 1 degree Centigrade lower unless in a fever state.
2) I can sleep through the night, and wake with a rested feeling. Previously I woke only to jump up in search of a sweet danish or coffee.
3) Now, no need to snack: I usually needed to eat sweets, or drink a beer, several times a day to maintain a calm disposition. If I couldn't carry something sweet / carby with me, I'd do anything to get to a shop and buy something.
4) I wasn't worried about my weight or skin, but once cutting carbs and sugar, I immediately lost all my belly fat (pants are loose) and my skin has cleared up completely.
I don't plan on giving up on this regimen; it will become my lifestyle instead of just a temporary experiment. Here is a pic of my now usual breakfast (taken on a particularly sunny morning, so with good light!); bacon and eggs, with the pumpkin, string bean, asparagus and broccoli glistening with coconut oil. Satisfying!