I've read where many folks, both men and women "thicken" with age. How pronounced this is, probably and a lot to do with your genetics. Posture plays a role too, I think. People who remember to keep their core strong, often by having good posture, probably don't have as much tendency to develop a distended gut. Certainly, lack of exercise and over-eating play a role in this too.
In my late teens, I had a 29" waist. Today it is 34". I'd be happier with 32", which seems obtainable if I continue to lose weight as I have done this past year. Clothes definitely fit better when you have a smaller waistline.