It has been drilled into us that our metabolism drops after 40. The truth is that our metabolism is a direct result of our lean muscle mass, the foods we ingest, and the amount of energy we require daily. Yes these things have changed from our 20s but it is still within our control!
Not only that, once you get your metabolism in check the amount of struggle to maintain your physique lessens. You do not need hours of cardio a day and salads only to maintain a lean physique. That is actually counter productive! I am a grandmother over 40 and enjoy the balance - and the body.