Being underweight would indicate that your Body Mass Index, or BMI, is below the standard weight. The BMI is calculated to estimate how heavy you are, given your height – or your mass spread over the square of your height. The importance of this measurement has ramifications for your health as a lack of proper nutrition or deficient intake means that you cannot perform certain body functions as normal. The way to come back to a normal weight is simple. All you have to do is eat, but that is where the simplicity ends. Eating just to put on weight could have serious consequences for your health if you do not do it correctly. For example, you could get really heavy by just eating fat, but that would be the wrong way to gain weight and you would just end up with flab and no muscle. Therefore, eating correctly and exercising correctly is the secret to good health.
The basic food groups that you have to concentrate on gain weight again is protein, carbohydrates, vitamins, minerals and very little fat. Fat is not just in the form of cheese and butter, but also in the form of cream and oil. To begin with, start to eat food with a limited amount of oil. The oil itself should be light plant oil like safflower or olive oil. Protein is one thing that you can actually gorge on and this can be in the form of animal protein, like dairy and meat, and plant protein like soy and legumes. Carbohydrates intake is important from the perspective of every day fuel required to get through the day. Therefore, the carbohydrate sources should only come from food, and not carbonated drinks and food with high sugar content. Vitamins and minerals will come from a good vegetarian diet of leafy green vegetables, soy, dairy, and if necessary supplements. Supplements are one addition that you cannot do away with because humans do not have the capability to acquire vitamins from plant sources – like vitamin B12. This supplement can only come from an animal source like meat and dairy.
Exercise is the final part of the puzzle. The day you start your diet is the day that you start exercising as well. This should start with simple toning exercises like walking and then progressing everyday to activities like jogging and running that eventually progresses to some basic weightlifting as well.