This took me probably too long to figure out.

As a kid i was always told to finish my plate, then the usual "think of the starving kids" guilt trips, and whatever else.

As an adult, I just eat smaller portions of the same garbage I ate before, and I started to lose a bit of weight. I didn't change anything else (at the time).

Now I'm working on the rest, but the biggest stepping stone for me was literally just eating smaller portions.