#uncat 

**Body-mass index** is a measure of the relationship between your weight and your height.

Originally invented in the 1840s by Belgian scientist Adolphe Quetelet (Кетле), the formula for the BMI is:
$$\LARGE BMI=\frac{W}{H^2}$$, where W is the weight in kilograms, and H is the height in meters.

Major criticism of the BMI is that because muscle weighs more than fat, a muscular person may have a higher BMI and technically classify as "overweight".

## Other facts
Sleep deprivation may cause an increase in one's BMI: 
1) not enough sleep -> too much **ghrelin** ([[Hunger and appetite|hunger]] hormone) and too little **leptin** (saturation hormone)
2) you're hungrier

## Alternatives
Other measures of fatness are:
- [[Bioelectric impedance]]: a body with more muscle than fat is less resistant to an outside electrical current (core principle)
- [[Air displacement plethysmography]]: subjects enter a chamber that measures body volume through the displacement of air in the chamber, which is then combined with body weight to calculate body density.
- [[DEXA]] (Dual-energy [[Рентгеновские лучи|X-ray]] absorptiometry): this test uses X-rays to measure muscle, bone, and body fat

Making the BMI more accurate in predicting health risks:
![[Pasted image 20240915233146.png]]