as vodka99 says, it's best if you do use all of your points in a day, unless you have a special occasion to save up for. The reason being that you may affect your weightloss by consistently undereating...
I tend to bank between 2 and 4 a day and on my wi day have Chinese meal and wine. Its great being able to bank them if youre going out, helps keep you on track even on a night out