BMI is a formula that is used to categorize body weight. To calculate BMI simply divide a person’s weight in kilograms (kg) by the square of their height in meters (m) to get a result in kg/m2.
Being underweight or overweight or obese has significant health. Low BMI risks include nutritional deficiencies, weakened immunity, fertility and osteoporosis. High BMI risks include cardiovascular disease, diabetes, joint problems and cancers.
BMI is useful as a quick tool to indicate if you have increased health risks. However, it is not always accurate in all circumstances. If you have any concerns regarding your weight consult your doctor. They will be able to advise you and order investigations if relevant.
https://www.nhs.uk/common-health-questions/lifestyle/what-is-the-body-mass-index-bmi/
https://www.diabetes.co.uk/bmi/how-accurate-is-bmi.html
https://www.medicalnewstoday.com/articles/265215#Authorities-still-promote-BMI
https://www.nhs.uk/live-well/healthy-weight/advice-for-underweight-adults/