Lol, yeah it all depends with weight, some ppl look heavier than they are and others look skinnier than they are. Ppl used to be surprised when mym mum used to say she weighed 52kg because they all thought she should weigh heaps less, lol. I dont know why tho, anyless and there wouldnt be anything left of her! Lol.
Im really short so at 64kg my bmi was 25 and i wanted to curb my bad eating habits before I got into the overweight range, so for me, 53kg isn't an unrealistic goal, because I am really short!
Good luck with it! Slow and steady wins the race so thats the best way to do it. It also means there is more chance the weight will stay off, which is what we all want!