You can also train yourself on how you eat. When I was eating a Keto type diet, I was surprised at how my feelings of hunger between meals (two a day spaced at 8 hours between) disappeared. And how my tastes largely changed so that I didn't want other foods. However, it was easy to slide if I let it. Training back to the old was easier than training to Keto. I switch was just enough that I didn't have to keep myself in line with total discipline. But the path to sliding was still staring at me.

So, people don't necessarily need to diet. They need to train their appetite just like they train their body.