Know Your Body Better: Check Your BMI



0.0
Underweight
< 18.5
Normal Weight
18.5–24.9
Overweight
25–29.9
Obese I
30–34.9
Obese II
35–39.9
Obese III
40+

What is BMI?

BMI (Body Mass Index) is a value derived from your height and weight. It is used to classify underweight, normal weight, overweight, and obesity in adults.

The formula for BMI is: BMI = weight (kg) / height² (m²)

It’s a simple way to assess if your body weight is in a healthy range. However, BMI does not account for muscle mass, bone density, or overall body composition.

Category BMI Range Indicator
Underweight < 18.5 May indicate nutritional deficiency or health issues
Normal 18.5 – 24.9 Considered healthy for most adults
Overweight 25 – 29.9 Risk of developing health problems
Obese I 30 - 34.9 Increased risk of health problems
Obese II 34.9 - 39.9 High risk of serious health conditions
Obese III 40 or more Extremely high risk; medical supervision advised

Risks of being Overweight

Being overweight increases the risk of a number of serious diseases and health conditions. Below is a list of said risks, according to the Centers for Disease Control and Prevention (CDC)
  • Heart disease – Too much fat can raise blood pressure and cholesterol
  • Type 2 diabetes – Body has trouble using insulin properly
  • Joint pain – Extra weight puts pressure on knees, hips, and back
  • Sleep problems – Fat near the neck can block breathing during sleep
  • Fatty liver – Fat builds up in the liver and can damage it
  • Cancer risk – Higher chance of getting breast, colon, or kidney cancer
  • Mental health – Can cause sadness, stress, and low confidence
  • Gallbladder issues – More likely to get stones or swelling in the gallbladder
  • Tiredness – Extra weight can make you feel tired quickly
  • Less movement – Harder to walk, run, or stay active for long

Risks of being Underweight

Being underweight can lead to several health problems and deficiencies. Below is a list of potential risks, as recognized by health experts and medical organizations
  • Weak immunity – Body can't fight infections easily
  • Low energy – Often feel tired or weak
  • Bone problems – Higher risk of weak bones or fractures
  • Hair loss – Hair may thin or fall due to lack of nutrients
  • Fertility issues – Can cause irregular periods or problems with pregnancy
  • Growth issues – Slower growth in teens or children
  • Skin problems – Dry or unhealthy skin due to poor nutrition
  • Cold sensitivity – Feel cold more often due to low body fat
  • Muscle loss – Body may start breaking down muscle for energy
  • Organ damage – In extreme cases, can affect heart or kidneys

LImitations of BMI

Although BMI is a useful tool for estimating healthy body weight, it has several limitations:
  • Only an estimate – BMI doesn’t directly measure body fat
  • Ignores body composition – Doesn’t show muscle, fat, or bone differences
  • May misclassify muscular people – Athletes may appear overweight due to muscle mass
  • Doesn’t account for age – Older adults may have more fat than younger people with same BMI
  • Gender differences – Women naturally have more fat than men at the same BMI
  • Ethnic variations – Health risks at certain BMI levels vary between ethnic groups
  • Activity level not included – Inactive people with normal BMI may still be unhealthy