Body mass index classification

The World Health Organisation (WHO) defines obesity as a body mass index (BMI) greater than or equal to 30 kg/m, where BMI is calculated as weight in kilogram divided by the square of height in metre. Table 7.1 shows the WHO classification in full. BMI is a simple index of obesity and correlates well with total adiposity, morbidity and mortality from many diseases. ... 

Classification Body mass index (kgjm ) Risk of co-morbidities... 

Table 15.1 Classification of Body Composition by Body Mass Index (BMI) and of Associated Comorbidities...

The top six traditional risks were C-reactive protein, systolic blood pressure, smoking, cholesterol, CAD history, and body mass index. The top six lipid species involved were phosphatidylcholine (PC) 34 5, PC 18 1/18 3, triglyceride 14 0/16 0/18 2, PC 28 0, sphingomyelin 18 2, and the odd carbon PC 33 3. When the two sets of risk factors were combined, the top six were PC 34 5, PC 18 1/18 3, C-reactive protein, triglyceride 14 0/16 0/18 2, PC 28 0, and systolic blood pressure. The results argue that models that include both lipids and traditional risk factors provide statistically more significant classification of unstable vs. stable CAD compared with models based on only traditional factors. 

Body mass index is calculated from the weight (in kilograms) divided by the square of the height (in metres) - i.e. BMI = weight (kg)/height (m). The desirable range, associated with optimum life expectancy, is between 20 and 25. As discussed in section 8.2, values of BMI below 20 are associated with undernutrition. Table 6.1 shows the classification of overweight and obesity by BMI. For older people, there is some evidence... 

Table 6.1 Classification of overweight and obesity by body mass index...

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