Oh Mel, that's really awful, I do feel for you as the same thing happened to me last week and I'd stuck to it all week apart from one meal out.
Was this your first week on Exante?
Did you drink enough water, as I know I didn't on the week I didn't lose?
Did you exercise too much as you can reduce your muscle mass which reduces your metabolism?
And as Colly says is it time of the month?
If none of the above apply then all you can do is continue and wait for a loss next week, it has to come off sometime! I am on target for about 4lb loss this week after losing nothing at all last week so it will get going again.
Keep your chin up and don't do what I did and have a meal and a drink to commiserate because the 'diet isn't working anyway!' It will work, honest
S x