This is something that has come to mind before, but rarely crystallised into a direct question. We are so used to assuming that diets should work-and granted logically speaking eating less calories in order to get your body to use up your fat stores makes perfect sense, in theory.
But what if weight loss diets did just work that way, what would that mean? It's worth asking this because of the fight the body puts up against dieting. It's extent and comprehensiveness is such that it has to be taken as more than mere rebellion for its own sake.
What has occurred is of none of this was there would there be anything stopping us from becoming anorexic?
Our bodies are primed to resist depression using a myriad of strategies and options to see it off, block its path or slow it down. Ironically part of that can be the adjustment of our appetites and/or eating.
Anorexia is said to happen due to stimulus plus genetic propensity. That varies from those who get the full condition and those who are able to life a lifestyle that skates the edge of it due to their application of focus.
I can't separate the relationship between that focus and the propensity to stick with calorie restriction as opposed to another focus of attention., but I think what stops diets from working is what is stopping us from keeping going and starving to death.
We have taught ourselves that we will stop way before we get to this point, or that dieting is one thing and this eating disorder quite another. But it seems more likely that these defences are all that is in the way of harm without them they'd be little to stop us keeping going except our reason, which may not survive, or even if it did is a thin thread on which to hang our will to live. If we did not fast to our deaths we can do serious harm long before that in some cases especially.
Anorexia can alter the perceptions significantly, to the point where it becomes virtually impossible to eat. I'm not sure whether that would be defensive in a situation of actual starvation. Undoubtedly it is still an unimaginably agonizing way to go.