
I agree that losing 10 kg in a month is too much. Safe weight loss is 1-2 lbs /week, which is 8-10 pounds/month; you're looking to lose twice that.
Of course, we'd all like to lose our weight right away, but first off, it doesn't happen that easily, secondly, in order to do it, we'd have to starve ourselves and as soon as we start eating again, we gain it all back.
Not good.