it really is just easiest to stick to the plan. Ive lost 6 stone in total and despite that i still occasionally have a planned meal...but when i do eat..BOY its so so hard to get back on track. each day off the diet is a day that you are further away from goal. Believe me, if you are really really determined enough then you may be ok and go back to the plan as normal with no glitches, but eating, even only a little, really does mess your head up and its so hard to get back 'in the zone'. last time i ate i got back on track the next day, but the day after that temptation to eat overcame me and it took me about a week to finally stop messing about and get back to it.(id go all day and be fine only to blow it on something stupid about 7pm)
But each person is different and you will only know how you will cope from experience.
xx