Maintaining the right body weight plays a major role in staying healthy and avoiding various health risks. 

Being underweight or overweight increases your risk of certain weight-related diseases. Your body mass index (BMI) is considered a major screening tool to estimate your weight status. 

What is BMI?

BMI is a measurement of a person's leanness or corpulence based on their height and weight and is intended to quantify tissue mass. 

It is widely used as a general indicator of whether a person has a healthy body weight for their height. 

Specifically, the value obtained from the calculation of BMI is used to categorize whether a person is underweight, normal weight, overweight, or obese depending on what range the value falls between. 

These ranges of BMI vary based on factors such as region and age and are sometimes further divided into subcategories such as severely underweight or severely obese. 

Being overweight or underweight can have significant health effects, so while BMI is an imperfect measure of healthy body weight, it is a useful indicator of whether any additional testing or action is required. 

Read on to understand the different bodyweight categories based on the BMI index.

How is BMI calculated?

BMI or body mass index is calculated by dividing your body weight in kilograms (kg) by the square of your height in metres (m2).

It is usually intended for adults, as children and adolescents are constantly growing, making it difficult to have a set value for the BMI cut-off. 

BMI Index 

BMI values indicate: 

  • BMI less than 18.5 - Underweight

  • BMI between 18.5 and 24.9 - Healthy weight 

  • BMI between 25.0 and 29.9 - Overweight

  • BMI of 30.0 or higher - Obese

What are the risks associated with being overweight?

Being overweight increases the risk of a number of serious diseases and health conditions. 

Below is a list of the said risks, according to the Centers for Disease Control and Prevention (CDC):

  • High blood pressure

  • Type 2 diabetes

  • Coronary heart disease

  • Stroke

  • Gallbladder disease

  • Osteoarthritis, a type of joint disease caused by the breakdown of joint cartilage

  • Sleep apnea and breathing problems

  • Certain cancers (endometrial, breast, colon, kidney, gallbladder, liver)

  • Low quality of life

  • Mental illnesses such as clinical depression, anxiety, and others

  • Body pains and difficulty with certain physical functions

  • Generally, an increased risk of mortality compared to those with a healthy BMI

  • High cholesterol levels (higher levels of LDL cholesterol, which is widely considered “bad cholesterol” &  lower levels of HDL cholesterol, which is considered to be “good cholesterol”)

As seen from the list above, there are numerous adverse effects that may result from being overweight. 

Generally, a person should try to maintain a BMI below 25 kg/m2 but ideally should consult their doctor to determine whether or not they need to make any changes to their lifestyle in order to be healthier.

What are the risks associated with being underweight?

Being underweight has its own associated risks, which includes the following:

  • Malnutrition and vitamin deficiencies.

  • Anaemia (a condition where you lack enough healthy red blood cells that carry oxygen throughout your body.)

  • Osteoporosis (a disease that weakens your bones and increases the risk of fractures).

  • A decrease in immune function.

  • Growth and development issues, particularly in children and teenagers.

  • Possible reproductive issues for women due to hormonal imbalances that can disrupt the menstrual cycle. 

  • Chances of miscarriage during the first trimester, which is commonly seen in women who are underweight.

  • Potential complications as a result of surgery.

  • Generally, an increased risk of mortality compared to those with a healthy BMI.

In some cases, being underweight can be a sign of some underlying condition or disease such as anorexia nervosa, which has its own risks. 

Consult your doctor if your weight is drastically high or low compared to the normal range, particularly if the reason for being underweight or overweight does not seem obvious.

 

Disclaimer: This article is written by the Practitioner for informational and educational purposes only. The content presented on this page should not be considered as a substitute for medical expertise. Please "DO NOT SELF-MEDICATE" and seek professional help regarding any health conditions or concerns. Practo will not be responsible for any act or omission arising from the interpretation of the content present on this page.