Of course, I realized tonight that laundry is enough to give me back problems! As I carried the laundry basket full of fluffy warm clothes upstairs, my back started to tighten up again.
I'm thinking the problem is two-fold. Yes, my gut is bigger, and it is putting a lot of stress on my spine and lower back muscles as gravity pulls it forward and down. The other problem is that, when I carry things, I have to carry them a few inches further away from my body than normal, because of my expanded waist. This, in turn, alters the lifting mechanics such that I am, by default, lifting more with my arms and back than is acceptable.
The frustrating thing is that I am not an inactive person. I play sports year-round: volleyball, softball, football, basketball, and occassionally tennis. It's not enough to lose weight or be in top shape, but it should be enough to maintain weight. I also don't eat too bad. I haven't touched fast food in a few years and eat mostly organic, whole grain, low fat, healthy foods...I just eat too much of them in general.
I need to get my act in gear and get aggressive about losing my gut, though, because I cannot stand being so out of shape that a little lifting incapacitates me.