Mo, just do what we did and move to a retirement location where you are nearly *always* the youngest ones there - even when your 50+.
Seriously though, living in Austin was making me feel a bit of what you are saying. It's a very young town. I had younger friends, young employees, young neighbors, etc. They seemed often as they would rather starve themselves than to gain a half a pound. And some would sort of "parade" around or try to show off in (to me) inappropriate ways. Like sitting without closed legs in their mini skirt, or wearing very tight fitting, low cut camisoles to go to work or out for dinner, then complain how cold they are the entire time. Often seemed to be really needing attention.
I'm fit, I workout, I eat really well. But I'm not going to do the 1200 calorie a day so I can be ripped thing. It's just not my personal style. I LOVE food and love cooking and wine, etc. And I would never do the "enhancement" thing, again it's just not my style. Not saying these women have, but you know what I mean.
I wonder how much you have in common with them though - I mean are they good friends, or just coworkers you are friendly with? Do you *feel* competition when you see them? I ask because if I felt competitive with a friend in a way that made me feel sort of like I wasn't looking forward to seeing them, or if I felt they were too "needy" with praise, it would probably be a sign that I need to expand my friendships to some other people for better balance. Nothing against them, but people who tout their beauty and hard work "too" much can really suck the fun out of their friends.