What do health experts say about BMI?

by Kaiser Permanente |
People of different sizes enjoying a healthy activity

Have you ever gone to the doctor for something like the flu — only to find yourself being weighed? You might have wondered, “What’s my weight got to do with this?” There’s a good chance your doctor was checking your body mass index, or BMI.

Health professionals use BMI to measure if you have a “healthy” amount of body fat. It’s a common tool used in health assessments and will most likely be used for a long time to come. But some have pointed out the flaws in using BMI as the only measure of body fat. 

In a new policy, the American Medical Association (AMA) advises doctors to look at more factors, in addition to BMI, to determine body fat.  

What is BMI, and why do doctors use it?

To calculate your BMI, doctors divide your weight by your height squared. The result assigns you to a category ranging from “underweight” to “severe obesity.” 

In the U.S., about 40% of adults are considered “overweight” or “obese” using this measurement.* BMI defines overweight and obesity as having an amount of body fat that puts your health at risk. They’ve been linked to other health issues like type 2 diabetes and high blood pressure. That’s why doctors often check to see where you fall on the scale. But not all health professionals agree that a normal BMI equals a healthy weight.

Stephanie Burke, MS, RD, is a registered dietitian for Kaiser Permanente in California. She points out that people with a “normal” BMI can have the same health complications as those who are “overweight” or “obese.” And people with an overweight BMI may not necessarily have health complications. 

This is one of many reasons the AMA has decided to move away from BMI as the sole measure of body fat. 

Other health factors to consider  

One-size-fits-all standards rarely apply, especially in health. “A better way to measure ‘healthy’ would be to take into account differences across racial and ethnic groups, sexes, and age span,” says Burke. 

Your daily lifestyle should also be considered. This is called social health and includes having a safe place to live, nutritious food, and good relationships. For many, finding social health resources isn’t easy. 

The AMA now advises doctors to consider BMI with other factors to determine body fat, like:

  • Visceral fat
  • Body adiposity index
  • Body composition
  • Relative fat mass
  • Waist circumference 
  • Genetic/metabolic factors

You can talk to a health professional about your health history to better understand how this information affects your personal health. But Burke cautions against getting too caught up in these measurements. 

“For some, examining numbers too closely can lead to weight stigma, which leads to more shame, dieting, and fluctuations in weight,” says Burke. “There’s a whole lot more to look at than just a calculated number.”

Lifestyle choices you can make to be a healthier, happier you

Taking care of your health goes beyond just weight. Burke suggests focusing on healthy behaviors that not only benefit your body but also build a positive relationship with yourself. 

Here are some ways to manage your health without restricting meals:

  • Find movement you enjoy. Exercise doesn’t have to be a chore. Explore physical activities that bring you joy — like taking a daily walk.
  • Don't skip meals. Regular meals help maintain a steady supply of nutrients and keep your body energized throughout the day. 
  • Don't cut out food groups. All foods can fit into a balanced diet. Aim for a balance of protein, carbohydrates, and healthy fats in each meal.
  • Add health-promoting foods to your diet. A good tip is to “eat the rainbow.” That means eating fruits and vegetables of different colors every day.
  • Explore intuitive eating. There’s a lot to learn about intuitive eating. In a nutshell, it means learning to eat mindfully without guilt.
  • Participate in a healthy lifestyle program. These personalized, online programs can help you create an action plan to reach your health goals.

Remember, your journey to health is as unique as you are. If you’d like help with nutrition, talk to your doctor or a registered dietitian. They can help you get started. For more information about health screenings you might need, try using our interactive tool.

*CDC, “Adult Obesity Facts,” accessed November 14, 2023.