Welcome to the HealthCareMagic Forum.It would have been nice if you had included your height also.If you want to reduce 20kgs you have to do the following things
1)Completely avoid fried,oily,sweets stuff,chocolates- till you lose 10-13 kilos.
2)Follow a strict exercise regime of 45-60 minutes daily without fail,including brisk walks,yogasanas,alternate day abdominal exercises
.Join a gym if possible and hire a trainer who would not only chart your exercise body part wise but also motivate you which is essential for weight loss
3)Include as much as raw food like fresh seasonal fruits, lots of green veggies,Buttermilk,Milk.
4)Lastly but the most important lose weight not to make you thin but aim to improve stamina and flexibility otherwise it becomes another chore.