It's too difficult to reduce 20kg in 40 days. Unhealthy. Eat only a little food in the morning and evening. Normal people eat a lot for lunch (especially fat people have a huge appetite). Besides, they can only drink water. It is forbidden to jog for an hour every day and eat any snacks and drinks (especially alcohol). 40 days minus 12 to 20 is enough. Losing weight is a step-by-step thing, and it is urgent.