Being overweight and having lost 35 lbs this year with plenty to go(I'm still overweight), I would say that you are more likely to work out and be active if you lose weight. That doesn't require much if any exercise, just an intelligent diet.

I'm not anti-exercise and I've worked out a lot in the past, but I've found that being skinnier makes being active easier and more fun. Moving sucks if you're carrying an extra 50-100 lbs. around. Most skinny people don't really get this.

So, I've focused on nailing the diet and that works for me. I basically didn't exercise more than once a week so far this year, but now that I'm down quite a bit, I am naturally finding myself to be more active.

In the long run both exercise and eating right are incredibly important, so if you're overweight and want to be more active, get rid of the extra weight and you might find yourself exercising more by default.