It almost seems that our body's metabolic systems--our glucose/insulin feedback system, in particular--was not made to last us for the lifespans that we are now capable of. Sometime around the late 30's to the mid 40's (happened around 38 to me) the metabolism slows down, as almost all of us develop cellular insulin resistance to some degree, abetted by the loss of muscle (which has more energy needs than most other body tissues except the brain).

I think you're basically doing the right thing--you want to be on a diet very low in simple carbs, and lower in carbs in general, than when you were younger, to give the insulin system some slack in not overreacting to sudden glucose floods (which it tends to slam right into fat cells at this point). Exercise is of course very important, and there seems to be some evidence that building muscle--or at least working not to lose it--may be even more important than aerobic fitness in normalizing the insulin system. Of course, this may not result in much weight loss--muscle weighs more than fat--but one can usually tell by one's body contours (and how one's clothes fit).

The other thing I find helpful is some version of the Zone eating paradigm--small, protein/fat/carb balanced meals several times a day (not two or three) to keep blood sugar/insulin reaction calm and measured. Big spikes from big meals--even if you're eating exactly the same amount of food over the course of a day--tend to result in more fat accumulation over time.

I've actually lost a few pounds over the last several weeks--I'd gotten up to 210 lbs., which is about 20-25 over what I should be. I tend to blame it on the gabapentin, which does have that carb crave/hypothalamus altering side effect--but I'm down to about 206, and I want to dump a few more before Thanksgiving comes along.