I've experienced the same situation when attending a school reunion. I went to an all girls' school, but we were associated with a private boys' school in the area. It wasn't the women who had changed (social pressures to look good maybe), but the men. These guys all played Rugby Union and were incredibly fit, but some lifestyle choices had not been physically kind to them. I did, however, stop and think of the choices that I had made - I'd taken up running and then through injury, cycling became my passion. This, coupled with no children and time and financial resources to participate in sport and other activities, gave me a lifestyle that enabled me to maintain my health and physical appearance.