I have a similar problem here. We get free drinks (i.e. bottled water, coke, juice etc) in work but every day the drinks man comes in to fill the fridge and brings two or three boxes of bars of chocolate (e.g. flakes, rolos, galaxy etc). Everyone on my desk ends up grabbing 4 or 5 each and because they know Im trying to avoid them, they take about 10 for me and put them on my desk. I always try and put them elsewhere but by mid-afternoon when your looking for a tea break there is always one or two lingering around and it is so hard to resist. It takes strong will power and I manage to do it most days but some days I just cant do it.