i find its about willpower and setting mini goals like instead of looking at it like i want to lose 15kgs but work towards mini goals of 5kgs first then when you make that one give yourself a treat and then onto the next mini goal!! thats what i find helps... i passed my first mini goal(i have it in my sig) and brought myself a nice top.. now the next goal of 5kgs not too long left!

hope that helps!!