How many calories should 23 year old weighing 55 kg eat to become 50kg?

How to lose 10 lbs. The only way to lose weight is to use more calories than one is eating or drinking in. Losing 10 pounds should take 10 weeks, and can happen if a person eats or drinks 500 calories less than he uses each day. For example, eat 1300 calories a day but use up 1800 each day. That means one can eat many calories, as long as he uses 500 more than he eats every day.