What is Body Mass Index (BMI)?

About Body Mass Index

The BMI scale is generally categorized as follows:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• obesity: BMI 30 or greater

BMI is a useful screening tool for identifying individuals who may be at risk for health problems related to body fat. It is widely used in public health, clinical settings, and research to assess population health trends and to guide health interventions. High BMI values, particularly those in the overweight and obese categories, are associated with an increased risk of several chronic diseases, including heart disease, diabetes, hypertension, and certain cancers. Conversely, low BMI values can indicate malnutrition or other health issues.

Despite its widespread use, BMI has certain limitations. It does not differentiate between muscle and fat mass, meaning that very muscular individuals may be classified as overweight or obese despite having low body fat levels. Similarly, it may not accurately reflect body fat distribution, which can vary significantly between individuals. For example, visceral fat (fat around the organs) poses a greater health risk than subcutaneous fat (fat under the skin), but BMI does not account for this difference.

Given these limitations, BMI is often used in conjunction with other measurements to provide a more comprehensive assessment of an individual's health. These additional measurements can include waist circumference, body composition analysis, and other clinical assessments to better understand the distribution and impact of body fat.