Pre dieting- This is when you've made up your mind, that you are going to start a dietary regime. Your appetite starts to lengthen itself and become more intense, in order to build up as many reserves against your intentions to starve it. No matter when you intend to begin, this will happen, if you decide that you will start after breakfast, your breakfast will be bigger, if it is Friday and you are starting on Monday, you will eat more from then on, whatever time you have, your appetite will expand as much as it can.Stage 2
Dieting itself- The body fights like fury throw you off the diet, this of course is a continuation of stage one, the body uses it's most powerful tools, in hunger and appetite to achieve this. The intensity hunger can reach can truly beggar belief, you mind can actually enter states associated with mental illness, depression, hallucination even psychosis.
If you survive this bit and continue, the body seems to change tack and can start to fade somewhat, gradually or suddenly. Sometimes it's the other way around, you start off and it's shockingly easy, literally no or little resistance, then out of nowhere-after losing a relatively small amount- you hit a wall, then it's becomes a total grind if you can continue at all.Stage 3
Post diet- That's when you either can no longer sustain the effort, or you finish your diet( and anything in between), the usual rebound of your hunger and appetite kicks in, as it is programmed to do.
It's very important that this is fully grasped, your body is supposed to make good the difference, however much you weigh, however little you have lost; a bit like when you donate your blood, your body replenishes that loss as fast and efficiently as it can.