Body Mass Index (BMI):It was invented in 1830 by Belgian statistician Adolphe Quetelet to gauge body size for public health purposes.
• It is calculated by dividing a patient's weight in kilogrammes by his height in metres squared.
• There are five categorisations: underweight (BMI of less than 18.5), normal weight (18.5-24.9), overweight (25-29.9), obese (30-39.9) and morbidly obese (40+).
• BMI gives an approximate view of the appropriateness of weight in relation to their height,
• It over-estimates fat in athletic individuals, and underestimates it in the elderly.
Body Volume Index (BVI):
• It will incorporate body volume, fat distribution, weight, size, shape, age, ethnicity, sex and other factors. Benchmarking will take place over coming years, and final categorisations are expected to be more minutely defined than in BMI.
• Numerical values are probable, but letters or "grades", or a combination of both, may be used instead, to place individuals in carefully partitioned categories for health assessment.
• Physical measurements will be taken using the BVI Scanner, a 5ft sq booth, using 16 light sensors and 32 cameras creating a computerised "virtual" body image and hundreds of linear data measurements in around seven seconds. Repeated scans will allow tracking of patients' progress.
For further information, see www.bodyvolume.com