Is body mass index (BMI) accurate?

Marjorie Nolan Cohn
Nutrition & Dietetics
BMI stands for body mass Index and is a measure of height to weight. It doesn’t take into consideration age or gender. Therefore is not the most reliable measure for obesity. It is however, and good rule of thumb tool when trying to determine your health risks associated with weight.

BMI Categories:

  • Underweight = <18.5
  • Normal weight = 18.5–24.9
  • Overweight = 25–29.9
  • Obesity = BMI of 30 or greater


Wendy Batts

There is a strong correlation between BMI and the amount of fat that someone carries on their frame. The strength of that reliability can vary by a few factors such as age and gender. For example: at the same BMI women tend to have more body fat than men, and at the same BMI older people tend to have more body fat than younger individuals. Given these variations, BMI is overall a strong predictor of body fatness and valid for the general population. Remember that BMI is only one measure used to predict the likelihood of developing weight related disease and that other health and lifestyle factors should be examined to assess your overall health.

Eric Beard
Sports Medicine
The Body Mass Index (BMI) is accurate but it only paints part of the picture of health and wellness. 

Body Mass Index (BMI) correlates an individual’s weight to their height. It helps to determine if someone is carrying too much fat on their body in relation to their height. there is much more to health or wellness than how much fat we carry around. A BMI score higher than 30 places individuals at risk for a host of health conditions and diseases but there is more to look at than just risk of disease. 

When looking at my clients wellness profile I pay attention to specific goals that they have in mind along with the following areas; bodyweight, body composition, flexibility, cardiorespiratory health, clothing size, quality of sleep, energy levels and possibly more depending on their goals. BMI is important, just remember to look at the big picture.
Body mass index is a simple and consistent method used to determine health risks and mortality rates associated with excessive body weight. Since BMI does not differentiate fat from lean body mass, a healthy athlete with a large amount of lean muscle mass can easily fall into the overweight, or even obese category, based on their BMI. Use BMI as a guide and make sure you continue to see your physician on a regular basis for annual physical check-ups.
Body mass index is an easy assessment that can be performed in order to estimate disease risk.  However, this should not be used in place of annual physical exams and other health tests.

Continue Learning about Body Mass Index (BMI)

Understanding the Obesity Pandemic
Understanding the Obesity Pandemic
What Are the Health Risks of Belly Fat?
What Are the Health Risks of Belly Fat?
What Is Obesity?
What Is Obesity?
Are Some Types of Body Fat Good for You?
Are Some Types of Body Fat Good for You?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.