One thing i found interesting is that as much as the manufacturers of clothing shifted the clothing sizes, average waist sizes still increased more than the clothing sizes did. IMO this highlights that the problem isn’t just their marketing but the food, diet, and overall health of the community impacts it as well. The medium size was supposed to reflect the median waist size, if waists are increasing, the measurements have to increase as well to maintain that status quo.

I have anecdotal evidence that similar trends sometimes happens to male clothing. I typically fit a medium pair of track pants perfectly. My parents bought me some track pants from costco, they got small and medium because they didn’t know my size. The small pair fits as if it were a large. My theory is the average costco male is a middle aged dad type, by making their sizes ridiculously big they can go home a feel good about fitting the medium pair instead of the large they typically wear.