Unfortunately that doesn't really work as a guiding principle. The body is entirely too easy to ignore, and social concerns ultimately are more important and urgent than personal ones. How exactly are you going to handle getting invited out to eat if you're not particularly hungry but could eat anyway? I had to answer this and way more in the year-long or so path to really getting serious about losing it and keeping it off.

And boredom is a real problem.

I liken trying to lose weight to trying to quit smoking. If all you had to fight were the nicotine cravings, nobody would be smoking today. It's the habits you have to fight, those things we build our life out of, and to fight habit you have to fix a lot of other parts of your life. Just finding ways to take five minute breaks that don't involve smoking. We want to treat these things in isolation, but they're not isolated, they all interact with each other. To do something like this forces you to deal with your entire life up to the present and be confronted with your own inadequacies. So there's that too.

Somebody who manages to quit smoking or lose weight and keep it off hasn't just managed to do that one thing, they've also managed to effect a complicated and difficult lifestyle change, and should by all rights be considered a completely different person. I don't feel particularly different from the me that was 210 pounds, but when I look at the big picture, I can understand why women aren't just being shallow when they wouldn't even look at me before, and now all seem to beg for attention.

That's why I focus at the level of lifestyle rather than on more mechanistic concerns like whether the keto diet is better than slow-carb and whatnot.