What is BMI?

Body Mass Index (BMI) is a simple, quick, and widely used method for assessing whether a person has a healthy body weight for a given height. BMI helps categorize individuals into different weight categories, such as underweight, normal weight, overweight, and obese.

The World Health Organization (WHO) classifies BMI into the following categories:

• Normal weight: BMI 18.5 – 24.9
• Overweight: BMI 25 – 29.9
• Underweight: BMI less than 18.5
• Obese: BMI 30 and above

More About BMI

Why BMI Matters

• Health Indicator: While BMI is not a direct measure of body fat, research shows that it correlates closely with more direct measures of body fat. A high BMI can be an indicator of high body fat, and low BMI can indicate low body fat.
• Identifying Health Risks: Different BMI ranges are associated with different health risks. For example, a high BMI is linked to an increased risk of chronic conditions such as heart disease, type 2 diabetes, and hypertension. On the other hand, a low BMI might indicate malnutrition, osteoporosis, and other health issues.
• Population Studies: BMI is used extensively in population health studies because it’s an easy, non-invasive, and cost-effective way to estimate the prevalence of underweight, overweight, and obesity within a population.

Limitations of BMI

• Does Not Measure Body Fat Directly: BMI does not differentiate between muscle and fat. A highly muscular person might have a high BMI but low body fat.
• Does Not Account for Distribution of Fat: BMI does not indicate where fat is distributed on the body, which is important as abdominal fat carries higher health risks.
• Varies by Age, Sex, and Ethnicity: BMI’s effectiveness can vary depending on age, sex, and ethnicity, making it less accurate for certain groups.