Eating until uncomfortably full, rather than the "hara hatchi bu" ("to 80% full") I heard about in Japan, has been my norm, and I'm paying for it now with acid reflux, GERD, and probably an over-accumulation of toxins (micro-plastics, forever chemicals, heavy metals, whatever), along with the extra cost of buying more than I need to survive and feel good.
Correct me if I'm wrong, but my guess is that our bodies can only digest so much food before peristalsis moves it out. Were I processing my solid waste for the garden (with soldier fly larvae or heat, etc) we'd have some decent, though costly, humanure (I do use my urine for the compost pile).
I feel best when I eat a massive salad (with all sorts of good stuff in it- sprouted grains & legumes, nutritional yeast, homemade ferments, oil and vinegar, garden greens and roots, sometimes meat) for brunch, a smaller meal mid-afternoon, and nothing else; this way I feel full all day (fiber is important for this) and empty enough before bed to be able to sleep through the night. When I get too stressed I eat emotionally, but I forgive myself and keep trying. Eating a cookie feels good in the moment and bad later on, while eating a salad takes more effort to do but feels both good in the moment (I like chewing, and the taste) and great for my mental health long afterwards.
Because agriculture is a contributor to climate change, eating just enough, with occasional celebratory "harvest feasts", feels like a good thing to do.
Granted, I am 21 years old and people always tell me that young people have a fast metabolism. I will see if that's true when I'm older.