Anyone here familiar with the term "middle-age spread"?
From experience I'd say there is the regular 'teen' growth that has probably stopped by your 20's. After that, weight gain is likely the main effect on shoe size.
If you put on weight (age/pregnancy) eventually your frame will enlarge to support the weight. Feet are not exempt.
At 8 stone I had size 7's. At 12 stone (and growing less) I have a size 8. I'm eating 2 meals a day, and trying to take regular exercise (walking in heels, what else?) I doubt my feet will get shorter, but they may get even narrower. I'm thinking a lighter me, will allow higher heels with less strain on the balls of my feet.
Teens are getting taller, and physics demand bigger feet to sustain this. Hence many stores selling size 9 in their range.
