First off, congratulations.
I'm not overweight, but I have noticed a few things in my life that I feel are worth noting. I've been fortunate enough to travel quite a bit and have noticed eating habits and food wherever I have gone. To preface this...I'm not a doctor...and might be crazy or stupid.
I've noticed three major differences between us and the rest of the world. I don't know which one is MORE important, but I think they all play a part.
1. Corn!!!! Everything we eat has corn in it. Read the label. This is how we fatten up livestock!
2. Hormones! Girls around the world don't get their periods at 11yrs old like here. Also transgender issues aren't as prevalent.
3. This is a big one. Portion control. In the US we eat to get FULL! This isn't necessary. Other cultures eat to not be hungry. My wife is from Central Europe. She would never super size it...or order an extra thing off the menu because she "can eat it". You just need to eat till you're not hungry...not till you are full.
I apologise if I'm way off with this. I think that a lot of this is a cultural problem here. We are all victims to it, to one degree or another.