BMI vs. Body Fat Percentage: Which Is a Better Indicator of Health?

Fact checked by Nick Blackmer

• Body fat percentage indicates how much of your weight is fat.

• Experts say whether your body fat percentage is high or low can affect your health, but it is only one measure to consider.

• Other health indicators include BMI, but also blood pressure, cholesterol, physical activity, stress levels, and sleep habits.
  

If you’ve previously only relied on your body mass index (BMI) to determine your health status, it may be time to consider another important measurement: your body fat percentage.

While BMI—which measures a person’s weight compared to their height—has historically been a quick and easy way to determine a person’s health status, the measurement alone could be misleading.

“BMI is often used to start the discussion for gathering other information,” said Claire Edgemon, RD, a senior registered dietitian at Baylor College of Medicine. “Since BMI is only looking at height and weight, people who have high muscle mass, like athletes, may have a BMI that suggests they are overweight.”

That’s when a body fat percentage measurement—which indicates how much of your weight is fat—can be a helpful addition.

“We want to make sure that someone identified as overweight by BMI is actually overweight,” said Edgemon. “Body fat percentage is just another measure that can help determine a person’s health status, so the more information we have, the better.”

Here’s more on what your body fat percentage can tell you about your overall health, how to calculate it, and what other variables to consider when determining your health status.

Body Fat Percentage vs. BMI

Body fat percentage is a measurement of how much of your weight comes from fat, as opposed to bone density, muscle mass, and weight from internal organs. Your body fat percentage can give you more insight into your overall health and risk of disease.

A person’s body fat percentage is different from their body mass index (BMI)—a measurement based on height and weight—but the two may be used together to give a more accurate look at a person’s overall health.

It should be noted that using BMI alone has been criticized in recent years for being an inaccurate health indicator, and therefore potentially harmful. Using the two measurements together—and understanding that they are simply estimates—is often more helpful.

“Different [measurement] methods might give you different numbers,” said Daniel Fulham O’Neill, MD, EdD, FAAOS, ABOS, a sports medicine doctor at The Alpine Clinic in Plymouth, New Hampshire.

“If [a person] winds up in a BMI or [body fat percentage] category significantly above or below the norm, that could be a health ‘red flag,’ but one number does not tell the whole story,” said O’Neill, adding that there are many other indices of health, including amount of physical activity, stress levels, and sleep habits.

Related: New Study Finds As Little As 2,600 Steps a Day Can Improve Your Health

Why the Emphasis on Body Composition?

“Having a high BMI or body fat percentage can set you up for multiple health issues,” said O’Neill. He mentions these include high blood pressure, high cholesterol, diabetes, heart disease, increased risks of many cancers, and so on. The World Health Organization notes specific cancers associated with obesity include endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon.

“The bad news is not just physical, as depression and other psychological issues have been associated with obesity,” said O’Neill. One literature review from 2020 found obesity is a risk factor for depression, especially in women.

“Abdominal obesity also increases risks for fatty liver disease, metabolic syndrome, breathing issues (sleep apnea, asthma), kidney issues, gallbladder issues, pancreas issues, and osteoarthritis,” Edgemon added.

Related: Does Muscle Weigh More Than Fat?

What Is a ‘Healthy’ Body Fat Percentage?

Every person needs some percentage of body fat. “We have body fat ranges for men and women based on age, athletic range, fitness range, acceptable range, and obese range,” said Edgemon.

According to O’Neill, the average acceptable body fat percentage is around or below 25%. Due to reproductive needs and biological differences, women generally have a higher body fat percentage than men.

For the most part, a healthy or “acceptable” body fat percentage for the average man is 18–24%; for women, that rises to 25–31%. Those who are physically fit or athletes will have a lower body fat percentage. Anything above the acceptable ranges for men and women is considered obese—but it’s important to note that those are averages and don’t take into account more personal features like age or ethnicity.

Conversely, anything below the essential fat range—2–5% for men, 10–13% for women—may also have a negative influence on a person’s health or may indicate an underlying health issue that needs to be addressed.

Related: BMI Is Outdated—Here's Why Your Waist-to-Hip Ratio Is a Better Indicator of Health

How Can You Find Your Body Fat Percentage?

If you’re interested in calculating your body fat percentage, there are several ways to figure it out—some more accessible than others.

“The most accurate ways to measure body fat are a DEXA (dual-energy X-ray absorptiometry) scan or underwater weighing,” said Edgemon.

DEXA scans measure body components that make up a person’s total body composition. This includes bone density, fat mass, and fat-free mass (muscles and organs). “It is often used to determine bone density or osteoporosis,” she said, adding that “underwater weighing requires being submerged 3 times and expelling all air.”

Though they are the most accurate ways to calculate body fat percentage, they’re also expensive and not always accessible.

“Other methods include skinfold measures using calipers, waist circumference measurement, waist-to-hip ratio (WHR), bioelectric impedance, and air displacement,” said Edgemon.

Research published in JAMA Network Open suggests that WHR may be more accurate than body mass index (BMI) in predicting associated health conditions.

To find your WHR, measure the waist at the smallest part (belly button, usually) and then the hip at the widest part, she said. “Ideally, the waist should be smaller than the hips.”

A WHR for men of at least 0.9 indicates abdominal obesity, for women, it’s at least 0.85.

O’Neill said your body fat percentage (and BMI) can be found simply by going to Calculator.net or many other sites and just putting in your information.

Keep in mind, however, that these measurements can only show you one part of your overall health. According to O’Neill, it’s best to also consider your blood pressure, weight, cholesterol, and other numbers for a broader look.

It’s also important to notice the trends of these measurements—so you can determine the direction your body is going in over time—and not rely on a singular reading. “Having some quantification can be useful to measure trends,” said O’Neill.

Related: Animal vs. Plant-Based Protein: Which Is Better for Weight Management?

How Best to Manage Body Composition

“Trying to ‘control’ or make significant changes in your body fat is a big ask,” said O’Neill. “You have no control over your genetics, or age, or the past years of not moving enough and eating poorly.”

“The real goal is getting off diabetes and cholesterol meds,” he added. “[As well as] having more fun on your holiday because you have more energy to tour the sites; having a tired puppy dog after a long walk in the park, et cetera.”

As adults, O’Neill said the easiest way we can gain control of our weight, but more importantly, health, is to reignite that physical identity we had in childhood. He explained physical identity is a child’s natural inclination to run, to explore, to engage with the outside world.

Edgemon agreed that physical activity, including both cardio and weight training, are good strategies for maintaining or reaching a healthy body fat percentage.

She also suggested staying within calorie recommendations to avoid excess fat storage and eating a “healthy” diet which means lots of fruits, vegetables, whole grains, lean meats, and dairy.

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