Well, I have been making a mod for Crusader Kings 2 which can be found in a general games thread that I more or less hijacked. Here’s a list of most of the features implemented thus far: Crusader Kings 2 - 3.0's weight gain - #646 by failmuseum
It’s not quite what you described, but it is a strategy game that has weight gain elements (which I greatly expanded on with my mod).