For the past three years I have began taking exercise more seriously. I was always an active kid that was involved in sports, so I never had to worry about my weight, and was just naturally skinny.
Nowadays, if I don't diet or exercise, I tend to hover around 215 or 220 pounds (I'm 6'1 or 6'2), which is a bit overweight. As of right now, I'm 185 pounds, and I try to go to the gym everyday, and I go swimming a few times a week, as weather permits. I spend 40 minutes on the treadmill with a 12 pound dumbbell in each hand, walking at a brisk 3.8 mph with a 6.0 incline. I also go on a walk with my wife and daughter a few times a week.
I tend to gain weight during the winter as I spend more time inside.
Actually, two years ago I had an unfortunate injury which occurred while at the gym. I must have pushed myself too far, and I ended up hurting my stomach while doing sit-ups. I went all winter without exercise. No joke, I was shitting blood. I never went to the doctor and it took several months to heal, and several more months before I felt comfortable exercising again.