I think this is the best place to ask this question:
Have any of you noticed a particular age when your metabolism noticeably slowed down?
Just curious about this.
You're not really looking at age precisely - for women you're looking at hormones, which of course age affects, but so does our habit for chucking birth control into our bodies like chemical warfare is going out of style. It's not an easy answer either because everybody's hormonal patterns are different just as a rule. It's like asking "at what age do you get your first period?" or "at what age do you go into menopause?" There's a general age range, but everybody is different. The biggest hormonal changes for women as adults are usually around early adulthood, then again at menopause.
If you've got good insurance, you might want to go to your doctor and have them check your hormone levels and see if something is out of balance. I've been thinking about it but my insurance is NOT good so I don't think I can afford it.
People also generally exercise less as they get older and that slows your metabolism down too. We get busier, our bodies start hurting on us, lots of reasons why. So it appears age has an affect on it, but it's our habits more than anything.