I was 78kgs and got it down to 67 in 2 months. This is what I did. I detailed it out in this post. My diet and the way of life described.
http://404phylenotfound.blogspot.com/2008/03/how-can-one-cut-down-his-weight-by-10.html Believe me it is not difficult at all..everyone can do it. Only in cases of hereditary/genetically acquired then might need medicines