It is an excellent tool to measure a person’s leanness or fatness as per height and weight. It widely describes whether your are in healthy zone or need to lose or gain weight. BMI ranges may vary based on your exercise regime. More you gain weight more will be the BMI but it does not mean that you are obese it can be because of high muscle mass also.
What Is Body Mass Index?
BMI is Body Mass Index a parameter to assess nutritional status as per height and weight. It is a ratio between weight in kilograms and height in square meters (1).
BMI chart Adults
Standard BMI ranges and nutritional status as per WHO
|18.5 – 24.9||Normal weight|
|30.0–34.9||Obesity class I|
|35.0–39.9||Obesity class II|
|Above 40||Obesity class III|
BMI chart Kids
BMI for age percentile is basically designed to assess growth pattern of children and teenage
|Weight Status Category||Percentile Range|
|Underweight||Less than the 5th percentile|
|Normal or Healthy Weight||5th percentile to less than the 85th percentile|
|Overweight||85th to less than the 95th percentile|
|Obese||Equal to or greater than the 95th percentile|
How to calculate body mass index?
In Metric Scale
Step 1: Measure your weight in kg preferably in an empty stomach to get actual weight.
Step 2: Measure height by Stadiometer and convert it to meter by dividing it by 100.
In Imperial Scale
Step 1: Measure weight in pounds by digital weighing machine.
Step 2: Multiply height in inches inself.
Step 3: Divide weight and height, results should be multiplied by 703.
BMI = Weight (kg) ÷ Height 2 (meter 2 )Imperial BMI Formula:
BMI = Weight (lb) ÷ height 2 (in 2 ) × 703
Risks of being overweight?
Overweight or severely obesity increases the risk of many diseases as per Postgraduate Medicine review studies :
- Cardiovascular disorders
- Metabolic Syndrome
- High Blood Pressure
- Gallbladder diseases
- Sleep Apnea and breathing problem
- Non Alcoholic Fatty Liver diseases
- Pulmonary Complications
- Low Quality of life
Risks for being underweight?
Being underweight multiple risks are associated with it:
- Low Bone Mineral Density
- Poor Immune System
- Retarded or stunted growth and development among children.
- Hormonal imbalance especially among women
Limitations of BMI
BMI is not an accurate measure when it comes to analyse body fat
- BMI measures overall nutritional status in relation to height and weight. No mention of body fat percentage or muscle mass.
- It does not distinguish water weight, bone mass etc.
- It is not specific to sex of a person. For eg: BMI of male and female is same whereas male has more muscle mass and female has more of fat mass which is not mentioned in BMI chart
What is a healthy BMI for women?
BMI varies as per age, height and weight. It is invariable in respect to gender. Though women have more fat mass compared to men but it does not affect BMI and no scientific evidence mentioned specific BMI for women.
- About child and teen BMI, Centers for Disease Control and Prevention. https://www.cdc.gov/healthyweight/assessing/bmi/childrens_bmi/about_childrens_bmi.html
- Body Mass Index- BMI, World Health Organization, Europe.
- The Medical Risks of Obesity, Postgraduate medicine, U.S. National Library of Medicine, National Institutes of Health.
- Body Mass Index: Considerations for Practitioners, Centers for Disease Control and Prevention.