Body volume allows for differentiation among persons of the same BMI , by assessing the distribution of fat through the various parts of the body, thus distinguishing the different body shapes.
The importance of body shape has been acknowledged, and user-friendly tools like "waist circumference" and WHR are currently in use. Attempting to move beyond these familiar methods, a BVI (body volume index) has been launched in 2007 with the aim of accurately measuring body shape for obesity, using a 3D scanner. Obviously, the BVI will prove much more cumbersome than BMI, WHR or "waist circumference" indexes.
It is complicated to determine with precision the volume of the human body. However, scientists found a very strong correlation between weight and volume, making it possible to estimate body volume with the help of the sole weight. For adult men, the volume of the body in litres is given by the equation:
volume (l) = 1.015 × weight (kg) – 4.937
SA÷V (Body surface area to volume) ratio
The relationship between surface area and volume (SA÷V ratio) is important to understand key processes in a number of disciplines, namely in biology. The leaves on trees provide an example of a species strategy to increase the surface to volume ratio in order to better perform the vital function of photosynthesis.
As humans are concerned, an increased surface area to volume ratio means higher exposure to the environment. This may play an important role in some clinical treatments or, on a more day-to-day level, it may raise problems of body temperature control or loss of water through perspiration in unfavourable environments.
[Reference: Correlation between body volume and body mass in men, D. K. Wakat et al, American Journal of Clinical Nutrition, Vol 24, 1308-1312, 1971.]