With such a undescriptive post sir/miss, it is hard to reply, which probably explains why you haven't received any replies thus far.

A little more about your lifestyle perhaps? What do you do for a living, do you have an active lifestyle, if so what do you do and how often. Experienced with exercise and do them constantly? What do you do on an average day in your life. All these are clues to this weight loss. I cannot even begin to surmise your 15 pounds missing if I don't even know if you have been training for the Olympics with the last 15 months, or you might have had a close relative passing away and have been grieving.