Sorry didn't see the title before the window opened, this is for the girl who lost 60 and put back on 20 and did the 1/2 marathon. Are you sure the weight you have gained is (fat) and not muscle? As muscle weighs more. I didn't understand how you gained 7 lbs when training for the 1/2 marathon. After you reached that goal, did you just stop? could be your goal weight and your maintenance weight based on your eating and new activity level (post marathon) are not the same as your activity level when you were training for the marathon. In other words your "normal" activity level may just be less intense, thus the gain.
What is your height? In the military I am 5'6" and my max was 142, and 135 was my lowest.