Body Mass Index of BMI is defined as weight in kilograms over height in meters squared. This indexing method is the most valid and reliable system for measuring obesity and overweight in people. BMI also provides a good correlation for the degree of risk of complications related to obesity such as heart disease.

The National Collaborating Center for Primary Care/the National Institute for Health and Clinical Excellence and the Department of Veterans Affairs/Department of Defense also use BMI to classify obesity and overweight:

† Underweight → BMI of 18.5 or lesser

† Normal Weight → 18.5 - 24.9

† Overweight → 25.0 - 29.9

† Obesity Class I → 30.0 - 34.9

† Obesity Class II → 35.0 - 39.9

† Obesity Class III → BMI of 40.0 or greater

Imperial BMI Formula

1 foot = 12 inches

Inches² = inches x inches

BMI = lbs / inches²

= (weight in pounds x 703) / height in inches²

Metric Imperial BMI Formula

1 meter = 100cm

Meters² = meters x meters

BMI = kgs / m²

= weight in kilograms / height in meters²

BMI of obese people are regularly monitored to manage the treatment efficiently and effectively. The waist measurement is also a vital factor in measuring risks, progress, and medication. Aside from BMI and waist measurement, other essential items for clinical assessment include physical examination, medical history, and laboratory tests.

In order to decrease BMI, it is also vital that the patients undergo psychological and social assessment in order to identify behavioral health situations that may affect therapy and patients’ desire to lose weight.