How i can lose weight in 3 weeks? my weight is 57 kg and i want lose 2 or 3 kg. please someone tell me!

Slow down: Eat healthfully. Try to eat at least 5 servings of vegetables & 4 of fruit per day. Increase nutritional fiber. Avoid refined sugar & junk carbohydrates. Avoid alcohol, sweetened juices, soda & caffeinated beverages. Aim for 7.5 to 8 hrs of sleep / night. Hydrate w at least 64 oz of water / day. Calories burned must > calories consumed. Do both cardio & weight training.

Speak with your docs: If you are already on a reduced calorie diet and an increased exercise program speak with your doctor about the details. If you are wanting to go on a reduced calorie diet with an exercise program review this as well. Avoid the fads, cleanses, and other costly quick weightloss gimmicks since they usually cause rebound. Good luck with your goals and hope you are able to keep it off.