Body volume index

The Body Volume Index (BVI) is a new measurement for obesity, proposed as an alternative to the Body Mass Index (BMI).

BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution (i.e. where different body mass is located on the body). People of different age, gender or ethnicity will have different body shapes and recent studies have highlighted the limitations of BMI as an indicator of individual health risk.

BVI as an application for body shape and obesity measurement
The Body Volume Index (BVI) was originally devised in February 2000 as a new, modern-day measurement for measuring obesity; an alternative to the Body Mass Index (BMI) which was originally conceived between 1830 and 1850.

BMI is based on height and weight only, but the new BVI system automatically measures BMI, waist circumference and waist-hip ratio in addition to highly sophisticated 3D volumetric and body composition analysis. It is projected that scientific and technical development of BVI may take a similar period to BMI, so 2020 is the current projected date for adoption and delivery on the scale required. By 2013 six scientific and seven academic institutions have been involved in the evaluation and validation of BVI as a potential new health risk measurement and indicator, which has been ongoing since March 2007.

BVI is an application that can be used on a 3D Full Body Scanner to determine individual health risk, whether the scanning hardware uses visible light optical information or otherwise. BVI allows for differentiation between people who are assigned the same BMI rating, but who have a different body shape and weight distribution, so that their individual BMI rating may not accurately reflect their own risk.BVI underwent clinical trials in the U.S. and Europe as part of a three year collaborative project, the Body Benchmark Study, the results of which were presented in October 2010 at a publicly funded launch in Birmingham, UK and scientific research and evaluation continued between 2011 and 2013.

Whereas the BMI of a person is measured manually by total weight and height, BVI is calculated by using 3D full body data to determine volume or weight distribution. BVI measures where the weight and the fat are distributed on a person's body, rather than the total weight or total fat content. There has been an acceptance in recent years that abdominal fat and weight around the abdomen constitute a greater health risk, commonly known as central obesity. A full body surface scanner determines the three-dimensional outline of a person's exterior surface, so that computation can be used to calculate the part volumes and the part body composition of that person. BVI makes an inference as to the body's distribution of weight and the distribution of muscle and fat, using complex and detailed Body Composition data.

Most 3D scanners suitable for BVI require that the subject is scanned for a series of images under varying lighting conditions (various projected patterns), to determine body shape and weight distribution data for individual patient and statistical analysis and BVI is currently under evaluation by government agencies in the UK as a possible long-term replacement for BMI.

BVI was conceived as a potential replacement for BMI at the turn of the millennium and after preliminary development, initial validation was undertaken by Heartlands Hospital, an NHS Obesity Centre in the UK. This was followed by clinical testing in the US by Mayo Clinic in Rochester, Minnesota. Other organisations such as Aston University, University of Hull and the Medical Research Council have also been involved in research and development of BVI.

An initial pilot study highlighted the potential of BVI as a motivational tool for weight loss in patients and as part of the Body Benchmark Study, a recent further study aimed to assess the validity and reproducibility of the BVI scanner in measuring anthropometric markers of obesity.

Comparative validation of the reliability of automatic measurement as opposed to manual measurement concluded that the scanner is a reliable, valid and reproducible method to measure waist and hip circumferences.

By late 2013, over 265,000 men, women and children have been safely scanned using the 3D technology originally developed for retail clothing measurement and now transferred to healthcare to develop BVI. These include assignment of BVI values for children aged 4–17, collation of 3D data in the US and Europe for normative reference data and development of an on-line BVI measurement system for wider usage and ease of access for measurement.