the first few days are hard, because of the physical effects of getting into ketosis. but that's not the only battle. psychologically you're bound to miss food. as you go on you're exposed to more and more situations where you feel weak, and unhelpful people. everytime you deal with one of those it's a challenge. but after a while, new situations and challenges come up that much more rarely. the first time i had to wait at a railways station and couldn't have a pasty, i cried. now i don't notice. but the other day i went to bluewater and there were all these yummy food concessions and it was hard again - because i hadn't been anywhere like that for a while.
it does get easier, because you get stronger - but it isn't ever easy as such.
the thing is, i think it is easier, for all that, than sticking to other diets for twice as long to get the same loss.