Hi, shedding 20 kilos within small duration can have a adverse effect on your health. You can try to reduce your weight over a period of time without affecting yourself. Do daily cycling and swimming each for 30-40 mins this helps you in faster burning of calories, do daily meditation and yoga to destress. Avoid smoking and alcohol. Take fresh sprouts and egg white, skimmed milk has low fat prefer that, use oats instead of foods rich in carbs. Include fibre rich vegetables and fruits in your diet. Avoid eating junk foods, prefer home cooked meals.take plenty of fluids to keep yourself hydrated.