>>105858777Homer takes a job interstate and spends most of his time elsewhere. Marge us unused to cooking for a family without him so continues to serve the same size meals, and refusing to let good food go to waste she eats it to set a good example for the kids. Combined with sexual frustrating at Homer's a sense and general boredom, she begins to settle into bad habits, such as binge eating and baking in order to keep herself busy, which of course leads to more binge eating.
Homer comes back every weekend to find her larger and larger and comments on how much she's changed, which hurts her self esteem, leading to more eating.