It's a very precise mechanism. Like breathing it is necesssary to life. No-one talks of 'intuitive breathing' even though it is affected by all sorts of things such as movement, stress levels, etc., it has to both to compensate for and adapt to these things.
We can regulate and vary our breathing within certain limits.
Similarly with eating, only our conscious input is likely to be more not as much as we imagined though. The most obvious route to controlling our eating is through the conscious mind, but that doesn't mean that control must be direct calorie manipulation.
The obviousness and showiness of the conscious part of eating means that we have made the mistake of thinking this it is the be all and end all of eating, that, if you think about it, cannot be.
Right now, do you know how your liver's doing for energy and nutrient requirements? Neither do I. I leave that up to my nervous system. It has the advantage of being directly connected to both my liver and my brain, so the information can be delivered efffortlessly to the part of my mind I'm directly aware of.
This works so well that even when it appears to be misbehaving, we cannot do it any better.