I have a strong sense that we are eating a diet that maintains a ketosis
metabolism.  We don't check for ketones or anything but we eat no sugars,
not more than a couple of fruit, and rarely drink fruit juices.  Out of
 >4000 daily calories maybe 50-75 grams are carbs are consumed.

It took a couple of weeks to establish a comfortable ketosis metabolism.
During the transition I was moody, sluggish feeling, and irregular. So, I
don't want to be doing that again.  However, after a couple of weeks I began
to feel great.  I felt much better than I ever remember feeling.  I noticed
a lot of positive changes. Another thing I noticed was when I ate sugar for
the first time (last time) it made me feel like throwing up.

So, the heart of my question is this.  We will eat fresh fruits and
vegetables every day and some days more than others.  Is there a threshold
of carbs that can not be exceeded before you stop your ketosis metabolism
and revert to some kind of glycogen metabolism.  It seems like I read that
the brain prefers ketones to glycogens but the muscles will burn glucose
reserves before processing fatty acids and therefore will not be creating
ketones if carbohydrate consumption rises to high.  There is quite a bit of
information on how to establish a ketosis state but not on how the opposite
process works.

How much is too much carbs?

Wayne