How to twist object maintaining uniform section? I have a long slender 'cylinder' with the following section that I'm trying to twist about the length (z-axis)

I've tried both the Lattice and Simple Deform modifiers but the center becomes thin like it's being stretched out.

It's what you would expect if you twisted an existing object but I'm looking for something more like a column of an old building.  This picture is not exactly what I want but close enough to illustrate the goal.

I've only been using Blender for a few weeks so I apologize if this is super simple.
Your topology lacks some horizontal edge loops, that's why it shrinks on its middle, so go in Edit mode, CtrlR then scroll (or +) to increase the amount of edge loops, then let's twist again!