Falling off the waggon...
We ate out every night and it's good to take a break from eating healthy / going to the gym regularly. I didn't feel the slightest bit guilty about having a starter, two mains and two desserts every night* for a couple of reasons:
1) In the same way as losing fat and building muscle take time, it also takes more than one week of eating rich food to really make a difference to your waistline. Sure, I've put on a couple of pounds and I look a little softer, but I know that in the long run, it's nothing.
2) Taking a total break from "dieting" is good for you, both psychologically and physiologically. If you're losing body fat, you're on a caloric deficit. You're probably on this deficit for a long time (see previous point as well as previous posts) so you might be running low on glycogen. Eating rich food, typically carbs, will replenish your glycogen stores and "reset" your body into thinking that food is plentiful. As long as you go back to the caloric deficit, you will carry on losing weight, possibly getting over any plateaus that may have occurred (fat loss is generally not a linear process - some weeks there'll be no change on the scales, other weeks a big change). Psychologically, taking a break is also good for obvious reasons.
Anyway, the important points are that taking a break once in a while is to be encouraged. Don't feel guilty about eating out once in a while, or even "pigging out" for a week but more importantly, get right back on with "dieting" afterwards.
Remember that in the same was as it taking several weeks of gradual fat loss to show in the mirror, the same is true of overeating - one meal or one day will not make a difference. But we all know too well that it's easier to gain weight than it is to lose it, so if you fall off the waggon, don't sweat it and just get back on.
*(I think I've already mentioned that I don't eat during the day simply for convenience, so my evening meals are big anyway).
Photo in this post courtesy of BenSpark: http://www.flickr.com/photos/abennett96/