> The problem is exactly that satiation doesn't work well enough, thus some people need a cybernetic add-on, just like some people need glasses.

Yes, but the important question is why. Why do an increasing fraction of people have broken metabolic feedback systems, and what can they do to fix them?

If we had cybernetic calorie counters that worked as reliably as glasses, it wouldn't be a big deal. But in practice, only a minority of people manage to stick to a calorie counting regime over the long term. And even the ones who succeed have to fight the battle their whole lives. It never becomes automatic.

That is why I think it's a mistake to pin people's hopes on calorie counting, when there is a lot of fascinating science about how to fix the built-in automatic system instead (see for example http://wholehealthsource.blogspot.com/, written by a biochemist who researches obesity and metabolism).