Hai tell me some methods to gain wait naturally ..also tell me some methods to improve digestion?

Why do you want to: Gain weight? At your age, if you are otherwise healthy, being skinny is not a disease. Deliberately gaining weight by overeating is likely to do harm. Eat a mixed diet of fresh vegetables, fruits, whole grains, nuts, legumes, beans, lentils, low fat milk products; limit intake of saturated fats. Exercise regularly. Above all do not obsess about being skinny.