To improve your weight you need to eat high protein, high carbohydrate diet along with fruits and vegetables.
Keep proper hydration and make yourself stressfree by doing some physical activity of your choice.
How much time it will take ,all depends on your physical condition,present or past history of any ailments or family history of lean body structure, your digestive system and strength.
Next Steps
tell me your present and past status to gind out the causes and act upon accordingly for best results
Health Tips
By the time Eat healthy balanced diet devided into 3 main and 3 small meals