Every time I lose a small amount of weight I go back to overeating, I think because once I can fit back in my clothes, my brain tells me that happy eating past that point must be a long-term commitment and therefore I'm fully giving up overeating.
Oh, Brain. They just stab you in the face sometimes, don't they? :-) You can start to dismantle that one by reminding yourself that happy eating is just that...happy! We pursue it because it's more enjoyable and sustainable than any alternative, not because it sucks and we lose weight. That would be a diet. If your take on happy eating feels enough like a diet to create resistance, maybe it needs some tweaking to include a lot more fun, flexibility, and occasional overeating. The thing to remember is that one or three or ten big meals still don't constitute overeating or result in weight gain if you're not eating more than you need overall, as in over weeks, months, and years. It's what you do the majority of the time that matters, and you can shift that in degrees versus all-crazy or all-restrained eating. The middle is what you're aiming for. To get there, you start where you are now. If you went from wildly overeating most of the time to slightly less overeating, you would still benefit and see results over time. So, it's not a choice between food chaos and a zen-like mastery of happy eating principles at all times. You'll always go back and forth to a degree. I do! That's why it's sustainable. No need to be perfect or even on guard at all times. Goofy eating is still welcome.