Okay so here is my theory on MY Personal weight gain. First I have never been smaller than a size 8, ever. Size 8 fits my frame very well and I am comfortable in that size. I am even comfortable up to a 12 in somethings. My ring size is an 8 or 8 1/2 depending on what hand so I am not a small person.
So from 1998 to 2005 I was a runner. G came home in 2005 (this is not her fault and I don't blame her). I remained a healthy steady weight and even ate appropriately. I also had a very high paying job for what I did. Granted I sold my soul during that time but I was financially well off.
In 2005 after G came home I tried to run with her in a running stroller but it totally freaked her out. There was no other option for me other than to not run. Treadmills freaked her out too. I was not getting babysitters for runs and I worked so late that there wasn't time in the evenings either.
In 2006 I made a very dreadful decision to leave the high paying job for self employment. The stress of trying to make it and failing plus having no money hit me extremely hard. Now I am still poor, literally, not making ends meet but I do have time to run. I am currently up to a size 16/18, no joke. I carry it fairly well in that until I lose it no one could really tell I weigh that much.
So here is what I think other than the non-running, I don't waste food. When I had money to burn, so to speak, I ate less in portion size. What I eat hasn't changed but now I cook a pizza for me and G, just a party pizza (jenos), and I eat 2/3 of it and G plays with 1/3. I don't feel right throwing any away. So I eat more. I actually finish my plate at restaurants and at home where as before I didn't I never finished a plate. I could afford not to. Now I can't and I see it as waste. I have to learn to waste again. In doing that I reduce my serving size and consume less calories.
Oh and for me it is all about calories. I could lose all of the weight by increasing the calorie output (running) and decreasing the calorie in put (portion size/calorie counting) and I can eat anything I want. I can't get motivated though to run again. I can't wear the shoes I have now and can't afford a new pair. I have had a fracture before stopping my 3rd marathon run. I can't do lots of training because I am prone to injury and illness. I actually trained for 4 marathons, the second I had a double ear infection on the day of it and just couldn't run it. The 4th one was the fracture. I completed the first and third ones.
Counting calories broke my gum chewing habit too. Gum chewing was a 10+year habit I broke in 2000 while training for my first marathon. I decided it was too many calories to consume without benefit.
So that is my theory on my personal weight gain. I am not a dieter and never will be.