chewing every bite thoroughly is a method I used about 10 years ago, and it worked. Lost 40 lbs, eating exactly what I wanted, but every bite must be chewed 30 times or "to a fine mush"...first of all, chewing a donut that thoroughly is NASSSSTY so although I could still eat whatever I want, I don't "want" donuts EVER again. (still can't stomach them) Unfortunately, potato chips are AWESOME chewed well!
Secondly, you really don't eat as much because you are eating so slow, and you naturally take in less calories, and lose weight. I still love to chew some foods to a pulp (raw spinach? oooh, yum!) and this was interesting: Meat isn't that terrific, chewed thoroughly. I would chew a bite and get all the juice out, then spit out the flavorless, dry chunk in a napkin or give it to the dog. blch.
mindful eating. It's a good practice, but it does take self-discipline, and I eventually quit chewing thoroughly and gained it all back.