My rise to obesity was 100% my fault. While there have been a few other extended family members with battles with obesity, it was not an inherited gene, but an inherited coping mechanism. Bored? Eat! Depressed? Eat! Taste of everything on the buffet! Finish your plate! Have a second helping! Pants too small? Buy another size!
I don't think this is valid for everyone, but in my own experience my weight has always been a "I stopped caring" situation. Also, once I paid attention to what a portion is really meant to be? My weight began normalizing.