Hi lybrate-user, you just overweight, loosing 20 kgs would be too much for your present weight and height. I feel loosing 8 kgs should be fine. Start exercising at least half to one hour a day. Cut down on sugars, sweet, carbohydrates like rice, potatoes, fried food, chips and wafers. And of course high calorie liquid like cold drinks and thick shakes, also alcohol. Increase the intake of vegetables and pulses and eggs. You can also have high protein low calorie protein powders as meal replacements. Oat bites and oat biscuits are good for snaking.