The internet is flooded with articles and tips for obese people who are struggling to lose weight. The dietitians, gyms, and weight-loss pill companies advertise assured weight loss. Besides all these, there is another set of people who struggle to gain weight and those who are envied by obese people. Yes, these are the underweight people. One may consider them to be lucky to have the liberty to enjoy all sorts of foods and still be lean and thin. But, do you know that these lean people are also struggling to gain weight and have their problems. Often, I have come across young boys and men who are lean and want to gain weight to have a good personality so that they can make an impression on others. And, if you are wondering why some people are underweight and what can help them gain weight, think no further. Keep reading to learn why certain people do not gain weight and what they can do about the same.

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Who is Termed as Underweight?
People who weigh less than their ideal weights or have a BMI (body mass index) less than 18.5 are termed as being underweight. BMI is calculated as the ratio of the person’s weight in (Kg) to his height in (Meter square) There are various online BMI calculators available.

The range of BMI is

  • Underweight – BMI is less than 18.5
  • Normal weight – BMI is 18.5-24.9
  • Overweight – BMI is 25-29.9
  • Obese – BMI is 30 and above

These BMI calculations would, however, not apply to certain populations, such as the elderly, growing children, athletes, and pregnant women.

Why are Some People Underweight?
Here are some reasons that explain why some individuals are underweight.
1.Some persons are building that way (lean) and it is their natural body frame.
2.Family History: Having a family history of being underweight can be another reason for an individual to weigh less. It is seen particularly observed in the cases of children. Parents themselves state that they were underweight when they were of their child’s age and gained weight later in their life.
3.Malnutrition: When the person does not eat nutritious food, he/she may be underweight. It could be due to poverty or lack of knowledge. For instance, a child/person eating just tea with roti due to the inability to afford food may be underweight.
4.Undernutrition: In this case, the person does not take adequate calories for putting on healthy weight, either due to poverty or due to the societal norms where being lean is considered a healthy sign.
5.Malabsorption: Here, the person is eating well but the small intestine is not able to absorb all the nutrients from the food effectively. The person may end up with weight loss if this continues.
6.Having a high metabolic rate: Some people naturally have a high metabolic rate and hence they burn the calories faster than others. This can also be observed in people who exercise a lot but do not take adequate calories to compensate for the calorie loss by increased metabolic rate.
7.Ailments: Certain illnesses, such as Hyperthyroid, Ulcerative colitis, Cancer, Tuberculosis, and HIV, can cause an unexplained weight loss in the patients.
8.Medications: Certain medications could cause nausea, vomiting, or a loss of appetite causing the person to lose weight.
9.Psychiatric illness: Psychological illnesses, such as chronic depression, anxiety, etc., could also cause a loss of appetite and weight loss.

Why Is It Not Good to be Underweight?

1.The underweight person may experience weakness, less stamina, and reduced productivity at work and in personal life.
2.Being underweight makes the person prone to reduced immunity and frequent infections.
3.Underweight people are prone to have weak bones and osteoporosis.
4.Underweight children may not be able to concentrate and have a good memory. Also, they may have improper development.
5.Underweight females may have irregular menses, problems with getting pregnant, and risk of miscarriage.
6.It also has a social impact, as the underweight person does not seem to be healthy or attractive to a potential partner or is not able to form a good impression while seeking a job.

How to Gain Weight Healthily?
Being underweight does not permit you to eat junk food or unhealthy food. Though junk food and processed food helps in weight gain, the calories associated with it are unhealthy and often come with a risk of health ailments, such as increased inflammation in the body, an increase in the levels of bad cholesterol, heart ailments, and diabetes.

To gain weight healthily, you need to follow the below guidelines –
1.Have a proper plan set up, which includes your diet plan as well as the exercise plan. This will help you be on track and reach your desired weight.
2.If you are experiencing an unexplained weight loss, visit your doctor to get the cause of weight loss diagnosed and corrected.
3.Eat healthy food: This includes 5-7 servings of fruits and vegetables in your daily diet.
4.Have lean meat
5.Eat small quantities of meals often: If you are suffering from a loss of appetite, due to the intake of medications, this tip will help.
6.Eat calorie-dense food: You can increase the calorie content of food by adding nuts/powdered nuts to the food. Add milk powder to the milk or pudding. Eat calorie-dense fruits, such as bananas, dried fruits, etc. Add flaxseeds to the chapatis or food. You can also add cow ghee to the rice or chapati. Raw ghee is known to have health benefits.
7.Avoid junk food, fried food, processed food, and carbonated drinks.
8.Exercises are not just meant for people to lose weight. Certain exercises, such as strength training exercises, can be beneficial for underweight people to build up the muscles and increase the weight. Avoid doing heavy cardio exercises as they are meant to burn the fat. You can do light cardio exercises though.

Got Questions? Get answers to all the questions regarding your ailment from Dr. Shah directly. Click here.

I hope this article provides you with enough insight into gaining weight. In case you have queries about your weight, do write to us at Or, call at 91 22 66888888. We shall be glad to assist you


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