A thin waist is often praised and glorified. A thin waist in particular and a thin person, in general, is constantly complimented for their figure. This mindset also prevailed in the past, and wherein women were forced to wear tight corsets to accentuate their curves, giving their body a thin or underweight appearance. However, the line between lean and underweight is often mistaken, and the diseases caused by being underweight are plenty.

Experts have now identified being underweight with many health problems. According to the American Dietetic Association, an individual is considered underweight if his BMI (body mass index) is below 20. If the BMI is around 17.5 to 18, then the person is deemed to be extremely underweight. Such an individual is devoid of many essential nutrients leading to a loss of energy and wasting. Wasting is a medical condition when the body does not get enough nutrients leading to retarded growth and a low height to weight ratio. Wasting is one of the parameters used by WHO to determine malnutrition.

Causes of Underweight:

 Various factors influence the weight of an individual. Even if two individuals receive the same amount of nutrition and undertake the same amount of energy-releasing physical activity, they will not have the same weight as there may be variation in the bone or the muscle density. Various reasons cause underweight. Some of them are:

1- Poor Nutrition:

Poor nutrition is one of the leading causes of being underweight. Many low-income countries have citizens who are malnourished. Such individuals have a low level of nutrition which leads to them being underweight. However, there is another set of underweight individuals devoid of nutrition not because of lack of money but because of bad eating habits.

2- Excessive Physical Activity:

Strenuous exercises can affect the body if proper nutrition is not available to the body. When calories are lost in excess, the body starts losing muscle and fat, which will lead to the person being underweight. In addition, in an individual who indulges in intense physical activity, the calories burn faster compared to people living a sedentary lifestyle. This is another major cause of being underweight.

3- Genetic make-up:

Genes can also be an important determinant of being underweight. For example, being thin and underweight can run in the family wherein the appetite is naturally low, or they possess a very active metabolism that hinders them from gaining weight.

4- Chronic Sickness:

The body’s metabolism can be hampered if the person is suffering from chronic diseases such as cancer. In such a case, the body’s energy is directed towards sustaining the individual’s life rather than contributing to weight gain. In addition, being Underweight can itself be a symptom that manifests due to other threatening diseases such as Diabetes, Thyroid or other such disorders.

5- Medication’s side effects:

Some medicines make the present loss of weight leading to underweight as one of the side effects. In addition, some medicines induce nausea which leaves the person devoid of essential nutrients and eventually renders them underweight.

6- Chronic Drug Abuse:

Chronic and prolonged drug abuse leaves the human body malnourished. For example, a drug addict rarely consumes the food necessary for his body; somewhat, his drug abuse not only hampers but recedes his growth leaving him skinny and frail.

Diseases caused by being underweight:

Illness caused by being underweight is now becoming more evident. Medical experts have associated many diseases with poor nutrition and low weight. Some of the most prominent health issues due to being underweight are:

1- Anorexia Nervosa-

Anorexia is a psychiatric illness wherein an individual is concerned about his weight and becomes obsessed with everything he eats. In such a situation, the individual starves themselves to a point where they can even become afraid of food. Though there is no physical examination to determine anorexia, it can be seen that such patients have a very poor caloric imbalance. As a result, such patients fear being overweight, resort to an extreme form of dieting, and are often accompanied by depression.

2- Osteoporosis or Bone degeneration­-

The risk of being underweight can lead to osteoporosis, wherein as one age, the bones become brittle and malnourished. When the bones become brittle, they can easily break. This increases the probability of frequent fractures.

3- Anemia-

Anaemia is a medical condition in which there is a low blood count of the individual. This can lead to several other health issues like dizziness, frequent fainting, fatigue and headaches.

4- Irregular menstrual cycle:

One of the illnesses caused by being underweight is that it may lead to an irregular menstrual cycle in women. Poor nourishment is often associated with low periods, and the menstrual cycle may be irregular or even absent. As a result, underweight women are at significant risk of being infertile.

5- Premature delivery of the baby:

One significant risk of being underweight is that babies born to malnourished mothers are often taken before their average period. If a baby is born premature, the baby is at risk due to many factors that are a direct result of the mother’s low weight- Frequent 6- Fatigue:

 Calories measure the energy a particular food can give to a person. Not getting sufficient calories can lead to fatigue and make the person prone to frequent illnesses such as cold, fever or even tuberculosis due to low immunity.

Hence, diseases caused by being underweight are in abundance. Therefore, one must be mindful of having a well-balanced diet wherein there is a sufficient quantity of all the macronutrients and the micronutrients required for the proper growth of both the mind and the body.