# Body mass index

BMIbody mass index (BMI)body-mass indexBMIsbody mass indicesnormal body weightnormal weightQuetelet IndexB'''ody-massBMI calculator
Body mass index (BMI) is a value derived from the mass (weight) and height of a person.wikipedia
504 Related Articles

### Human body weight

body weightbody massweight
The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m 2, resulting from mass in kilograms and height in metres. The modern term "body mass index" (BMI) for the ratio of human body weight to squared height was coined in a paper published in the July 1972 edition of the Journal of Chronic Diseases by Ancel Keys and others.
Other methods used in estimating the ideal body weight are body mass index and the Hamwi method.

Adolphe Quetelet, a Belgian astronomer, mathematician, statistician, and sociologist, devised the basis of the BMI between 1830 and 1850 as he developed what he called "social physics".
He founded the science of anthropometry and developed the body mass index scale, originally called the Quetelet Index.

### Underweight

thinnessskinnylow weight
For such individuals, the value recommendations are as follows: a BMI from 18.5 up to 25 kg/m 2 may indicate optimal weight, a BMI lower than 18.5 suggests the person is underweight, a number from 25 up to 30 may indicate the person is overweight, and a number from 30 upwards suggests the person is obese.
Underweight people have a body mass index (BMI) of under 18.5 or a weight 15% to 20% below that normal for their age and height group.

### Obesity

obesemorbidly obeseoverweight
For such individuals, the value recommendations are as follows: a BMI from 18.5 up to 25 kg/m 2 may indicate optimal weight, a BMI lower than 18.5 suggests the person is underweight, a number from 25 up to 30 may indicate the person is overweight, and a number from 30 upwards suggests the person is obese.
People are generally considered obese when their body mass index (BMI), a measurement obtained by dividing a person's weight by the square of the person's height, is over 30 kg/m2; the range 25 kg/m2 is defined as overweight.

### Overweight

big-bonedexcess body weightexcess weight
For such individuals, the value recommendations are as follows: a BMI from 18.5 up to 25 kg/m 2 may indicate optimal weight, a BMI lower than 18.5 suggests the person is underweight, a number from 25 up to 30 may indicate the person is overweight, and a number from 30 upwards suggests the person is obese.

### Anorexia nervosa

anorexiaanorexicanorexics
In the United States, BMI is also used as a measure of underweight, owing to advocacy on behalf of those with eating disorders, such as anorexia nervosa and bulimia nervosa.
The severity of disease is based on body mass index (BMI) in adults with mild disease having a BMI of greater than 17, moderate a BMI of 16 to 17, severe a BMI of 15 to 16, and extreme a BMI less than 15.

### Type 2 diabetes

diabetes mellitus type 2type II diabetestype 2 diabetes mellitus
People from different ethnic groups, populations, and descent have different associations between BMI, percentage of body fat, and health risks, with a higher risk of type 2 diabetes mellitus and atherosclerotic cardiovascular disease at BMIs lower than the WHO cut-off point for overweight, 25 kg/m 2, although the cut-off for observed risk varies among different populations.
Lifestyle factors are important to the development of type 2 diabetes, including obesity and being overweight (defined by a body mass index of greater than 25), lack of physical activity, poor diet, stress, and urbanization.

### Diabetes

diabetes mellitusdiabeticdiabetics
In Singapore, the BMI cut-off figures were revised in 2005, motivated by studies showing that many Asian populations, including Singaporeans, have higher proportion of body fat and increased risk for cardiovascular diseases and diabetes mellitus, compared with general BMI recommendations in other countries.
A number of lifestyle factors are known to be important to the development of type 2 diabetes, including obesity (defined by a body mass index of greater than 30), lack of physical activity, poor diet, stress, and urbanization.

### Ancel Keys

Ancel KeyesDr. Ancel Keys
The modern term "body mass index" (BMI) for the ratio of human body weight to squared height was coined in a paper published in the July 1972 edition of the Journal of Chronic Diseases by Ancel Keys and others.
In a 1972 article, Keys and his coauthors promoted Adolphe Quetelet's body mass index (BMI) as the best of various indices of obesity, which the U.S. National Institutes of Health then popularized in 1985.

### Breast cancer

breastbreast carcinomabreast cancers
This implies that the food one eats is of greater importance than ones BMI.

### Classification of obesity

Body volume indexbody mass indexBVI
For example, the BMI of bodybuilder and eight-time Mr. Olympia Ronnie Coleman was 41.8 at his peak physical condition, which would be considered morbidly obese.
The World Health Organization (WHO) classifies obesity by body mass index (BMI).

### Body fat percentage

body fatfat masspercentage body fat
Conversely, large framed (or tall) individuals may be quite healthy, with a fairly low body fat percentage, but be classified as overweight by BMI.
The widely used body mass index (BMI) provides a measure that allows the comparison of the adiposity of individuals of different heights and weights.

### Body composition

fat free massbody composition monitorsfat free mass (FFM)
BMI was designed to be used as a simple means of classifying average sedentary (physically inactive) populations, with an average body composition.

### Waist-to-height ratio

Index of Central Obesitywaist-to-height ratio WHtRWaist-to-stature ratio
However, falling into one's ideal weight range for height and build is still not as accurate in determining health risk factors as waist-to-height ratio and actual body fat percentage.
A 2010 study that followed 11,000 subjects for up to eight years concluded that WHtR is a much better measure of the risk of heart attack, stroke or death than the more widely used body mass index.

A prospective study in 1994 noted that body mass index remains the strongest predictor of symptomatic gallstones among young women.

### Waist–hip ratio

waist-hip ratiowaist-to-hip ratiowaist to hip ratio
A 2011 study that followed 60,000 participants for up to 13 years found that waist–hip ratio was a better predictor of ischaemic heart disease mortality.
The WHO states that abdominal obesity is defined as a waist-hip ratio above 0.90 for males and above 0.85 for females, or a body mass index (BMI) above 30.0.

### Hypertension

high blood pressurehypertensivearterial hypertension

### Corpulence index

Ponderal indexRohrer's index
In comparison, the Ponderal index is based on the natural scaling of mass with the third power of the height.
It is similar to the body mass index, but the mass is normalized with the third power of body height rather than the second power.

### Nick Trefethen

Lloyd N. TrefethenLloyd Nicholas TrefethenProfessor L. N. Trefethen
According to mathematician Nick Trefethen, "BMI divides the weight by too large a number for short people and too small a number for tall people. So short people are misled into thinking that they are thinner than they are, and tall people are misled into thinking they are fatter."
In 2013 he proposed a new formula to calculate the BMI of a person:

### Body Shape Index

A Body Shape Index (ABSI)
Data on 11,808 subjects from the National Health and Human Nutrition Examination Surveys (NHANES) 1999–2004, showed that SBSI outperformed BMI, waist circumference, and A Body Shape Index (ABSI), an alternative to BMI.
The inclusion of the latter is believed to make the BSI a better indicator of risk of mortality from excess weight than the standard body mass index.

It further postulates that normal to low body mass index or normal values of cholesterol may be detrimental and associated with higher mortality in asymptomatic people.

### Body surface area

body surfacebody surface area (BSA)body surfaces
The Surface-based Body Shape Index (SBSI) is far more rigorous and is based upon four key measurements: the body surface area (BSA), vertical trunk circumference (VTC), waist circumference (WC) and height (H).
There is some evidence that BSA values are less accurate at extremes of height and weight, where Body Mass Index may be a better estimate (for hemodynamic parameters).

### Relative Fat Mass

RFM is a simple anthropometric procedure that is claimed to be more convenient than body fat percentage and more accurate than the traditional body mass index (BMI).

### Somatotype and constitutional psychology

somatotypesomatotypesmesomorphic

### Mass

inertial massgravitational massweight
Body mass index (BMI) is a value derived from the mass (weight) and height of a person.