I'm a rather thin guy ... been so all my life ... but when I hit the big 4 - 0, I accumulated about 5-10 lbs in the typical love-handles sections ... tummy and kidneys. I've been working out more, running twice per week and snacking less.
I went from 162lbs to 157lbs in the last 2 months. For someone who has been in great shape all my life, I can't believe how much work that was. When I was younger, I could add or drop 10 pounds in 2 weeks without trying hard.
As I get even older, I suspect I'll get more 'aero' as well.