<unk>  <unk>  is a value derived from the<unk>  (weight) and height of a person. The<unk>  is defined as the body<unk>  divided by the square of the body height, and is expressed in units of kg/m2, resulting from<unk>  in kilograms and height in metres. The<unk>  may be determined using a table or chart which displays<unk>  as a function of<unk>  and height using contour lines or colours for different<unk>  categories, and which may use other units of measurement (converted to metric units for the calculation). The<unk>  is a convenient rule of thumb used to broadly categorize a person as underweight, normal weight, overweight, or obese based on tissue<unk>  (muscle, fat, and bone) and height. Major adult<unk>  classifications are underweight (under 18.5 kg/m2), normal weight (18.5 to 24.9), overweight (25 to 29.9), and obese (30 or more). When used to predict an individual's health, rather than as a statistical measurement for groups, the<unk>  has limitations that can make it less useful than some of the alternatives, especially when applied to individuals with abdominal obesity, short stature, or unusually high muscle<unk> .<unk> s under 20 and over 25 have been associated with higher all-cause mortality, with the risk increasing with distance from the 20–25 range.
Body mass index
Body adiposity index
Obesity
Lean body mass
Family history 
Body fat percentage
Body composition
Sedentary lifestyle