Obesity Treatment Bmi

BMI, or body mass index, is a statistical measurement of a person’s body fat based on her height and weight. The formula used to calculate BMI scores was developed by a Belgium statistician named Adolphe Quetelet (1796-1874). While BMI scores have some limitations, they are generally a reliable measurement of a person’s body fat.

What BMI Scores Mean

According to the National Heart Lung and Blood Institute, the following BMI scores correspond to specific weight conditions in adult men and women:

  • A BMI of less than 18.5: Underweight
  • A BMI of 18.5 to 24.9: Normal weight
  • A BMI of 25 to 29.9: Overweight
  • A BMI of 30 or more: Obese.

A person with a BMI of 40 or more is said to be suffering from morbid obesity, a dangerous condition associated with serious health complications. A person may also be considered morbidly obese with a BMI score over 35 when accompanied by obesity-related health complications such as hypertension, diabetes or heart disease. Anyone weighing more than 100 pounds over his ideal weight is also considered morbidly obese.

How to Calculate BMI without an Obesity Calculator

The formula used to calculate BMI is fairly simple. Using imperial (English) measurements, a person’s BMI is calculated by multiplying weight in pounds by 703 and dividing the result by height in inches squared. Online obesity calculators are readily available, however, so there’s no need to calculate BMI manually.

Limitations of Obesity Calculators

While BMI scores are a reliable indicator of body fat for most people, a BMI can sometimes provide skewed results. Athletes, weightlifters and people with muscular builds will have relatively high body mass index scores, as muscle weighs more than fat. The BMI score in such circumstances may indicate the individual is overweight or obese, when her body fat is actually lower than normal.

By the same token, a BMI score may underestimate body fat in people who have lost muscle mass, either due to aging or illness. For the majority of people, however, BMI offers an accurate appraisal of body fat.

Obese Children and BMI Scores

While obesity calculators provide accurate BMI scores for adult men and women, the use of BMI in children is controversial. A child’s body mass index fluctuates based on age and growth, and can change rapidly over a short period of time. A doctor examining a child for obesity will consider the child’s age, gender and body frame, in addition to BMI score.


Centers for Disease Control and Prevention. (2009). Body mass index. Retrieved April 25, 2010, from http://www.cdc.gov/healthyweight/assessing/bmi/.

MediLexicon International. (n.d.). What is obesity? Retrieved April 25, 2010, from http://www.medicalnewstoday.com/info/obesity/what-is-obesity.php.

National Heart Lung and Blood Institute. (n.d.). Aiming for a healthy weight. Retrieved April 25, 2010, from http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/risk.htm#limitations.

Obesity Action Coalition Staff. (n.d.). All about obesity. Retrieved April 26, 2010, from http://www.obesityaction.org/aboutobesity/morbidobesity/mo.php.

What Health. (n.d.). How to calculate BMI. Retrieved April 25, 2010, from http://www.whathealth.com/bmi/formula.html.