Overate* Sorry, I'm a teacher and its automatic
You lose and gain weight for a variety of reasons, only one of which is your calories consumed. Water weight plays a huge part, due to how much sodium you consume, what exercises you have been doing, etc. Also, weight loss/gain doesn't occur as you are eating the item, it has to do with long term eating and exercise habits. Your calories may have still averaged at a deficit for the week. Sometimes weight makes no sense. For example, yesterday I was smack bang in the middle of my ranges, didn't eat any sweets, and I'm up nearly a kilo today!