I suppose it's possible - I lost over half a stone over the 3 weeks of exams without even trying, but I think that was due to stress.
I'd recommend exercise (swimming, jogging, etc.) regularly, maybe 45 minutes a day or so.
In terms of food, just cut down on snacks. If you have to snack, eat carrots or something. Eating 3 decent sized meals a day (maybe slightly smaller than normal but not ridiculously) will be better in the long term than starving yourself.
Having said all that, size 8 is fine and you should be happy with that, but you probably know that already and other people will doubtless say it.
I'm not an expert or anything so my advice may not be good