In order to loss "weight" you need to be in a calorie deficient diet,
Y=the amount of calories you need to "maintain" your current weight daily
Y-500calories per day x 7 days in a week=3500 calories
theres 3500 calories in a pound of fat
http://www.freedieting.com/tools/calorie_calculator.htm
its better to determine your daily requirement of calories by weighting your yourself and counting calories with out gaining or losing a pound over a certain period of time.
In order change your body composition "fat to lean mass" you must work out intensly and follow the paleo diet.
http://en.wikipedia.org/wiki/High_intensity_training
http://baye.com/
Paleo diet
http://altmed.creighton.edu/Paleodiet/Foodlist.html
CHAT