Weight / Fat loss

I was having a chat with some other guys who are doing ironman training at the moment during yesterday's run about the hunger monster that occasionally catches you and requires serious fridge raiding to satiate, I'm sure there must be some research on why this happens....

I get the feeling that you can increase training and eat the same for quite some time before the deposit catches up.

Which I Guess if impressive of the human body. But its also a bit silly that you feel fine for days untill some glycogen Level alarm goes off. At which point you have to eat a tub of Ben'nJerrys just to achieve normal hunger.

Kinda like owning a car With a petrol gauge that always reads 'nuff petrol', then suddenly switches to 'no petrol, add NItros and rocket fuel'