Oh god, sue ... you really are me 
Mmmm, good question ... there's actually more about my lifestyle that helps me gain weight actually! Sitting on my arse in front of the PC doesn't help, nor does seeing food as a comfort. I suffer with depression, and when I'm feeling down I binge.
But ... there has to be some positives. So, let's think ...
I'm vegetarian, and eat loads of fruit and vegetables.
I'm teetotal.
Me and dd walk to school and back every day, so that's at least an hour and three quarters walking everyday (although half of it is at dd's pace!) - in fact I walk everywhere, so I do a lot more than that.
I like gardening, so getting out into the garden and doing stuff helps too.
Er ... er ... running out of positives now!