How to loose weight without exercises?

i am working person where i have to sit for 8-9 hours daily and really dont get time to excercise in whole day and put on weight after pregnancy,i want to loose weight atleast 8-10 kgs in atleast 6 months,is there any diet plan through which i can achieve this,i have determined to go to any level of dieting to loose weight ..........pls help me with some serious answers