Hello Jinal, welcome to HealthcareMagic forum! A healthy increase in body weight can achieved by a well planned diet and exercise schedule. Follow a well balanced diet with adequate intake of carbohydrates, proteins, fats, vitamins and minerals. Drink plenty of water and exercise regularly; preferably on a daily basis. I advise you to visit a nutritionist who would suggest a diet chart based on your height,weight, and your activity. It would be nice if you go for weight lifting under a qualified trainer, in order to build up muscle. Combination of a healthy diet, aerobic exercise and anaerobic exercise(weight lifting) is a good way to put on weight in a healthy manner! Best wishes and regards.