Don't assume its menopausal and that there is nothing you can do about it just yet!  I'm in my 60s (not for much longer!) and have only in the last 18 months begun to get a bit tight in my trousers!
I think you should look very carefully at your diet and make sure you aren't eating too much of something that bloats you.  With me its bread, and home made bread especially.  (I just LOVE it) If I cut that down I definitely get less bloated.  Google up 'food combining' - that's worth consideration too.  It's a bit awkward to instigate if you have a family, but may be worth the effort.  There are several books about it and usually contain a collection of recipes along with the interesting info. Doris Grant & Jean Joice have written 'Food Combining for Health' It's a British book (Thorsons) but maybe Amazon could get you a copy of it if you haven't got an alternative over there. (though I expect you have).  You may find riding hilly routes will help to strengthen tummy muscles too. 
Lots of luck!
P.S.  My DH has just walked in from the shops with a HUGH Danish pastry - can I resist it?  Answers please on a postcard.......
