Anyone who is 15-20 percent below the normal weight, with respect to their age and height, is defined as underweight. For example, if you are a female aged between 25-50 years, and your height is 1.68 meters, your weight should ideally be 59kgs. However, when the body weight falls to 50 kg (15%) and 47 kg (20%), it is termed as underweight.

If you want to gain weight healthily, the quickest method is by changing your eating habits. For a woman trying to lose a pound per week, she should try to eat 500 calories less than burned on a daily basis. When you are trying to gain weight, this process should be reversed. The easiest way this can be achieved is by consuming your normal healthy meal plan along with protein shakes, but with the addition of other meal replacement drinks. Typically, meal replacement drinks are consumed in place of a meal, and they contain a moderate amount of calories, protein, and carbs like Full cream milk,Beans, lentils, and other such protein-rich foods,Fruits and vegetables,Cereals,Healthy fats and oils,Healthy desserts