"...it still seems to me that it is indeed possible to take in more
calories than you expend and not gain weight on low carb."

I meant to say that, although the above is true, gluttony was still a vice
to our paleo forebears even without access to Krispy Kreme doughnuts.  It
possible, of course, to overeat on low carb and gain weight as long as the
energy obtained from fat and protein is more than your daily energy needs
AND the following two items are subtracted from straight calories from fat
and protein : 1) the inefficiencies of gluconeogenesis; as well as 2) the
body's protein and fat needs are met prior to its energy needs.