This is what the above post is referring to.
https://twitter.com/ToddWitteles/status/1783651615725273241
The weight gain was actually mostly between September 2023 and February 2024, when a persistent foot problem made me extremely sedentary, as it was painful enough to walk to where I kept it to a minimum, even around the house.
The problem has mostly resolved itself, only occasionally flaring up. Now I need to lose the weight.