Body Mass Index (BMI) has historically been the default way to determine whether someone is at a “healthy” weight. BMI only compares height and weight, which leaves out the distinction between fat and muscle. It also does not account for body shape and was never designed to reflect the diversity of human bodies. These limitations called for the American Medical Association (AMA) to recommend that clinicians de‑emphasize BMI. The organization noted that BMI was developed using data from non‑Hispanic white men and has contributed to racist exclusion and historical harm due to the misidentification of the weight status of many racial and ethnic groups.
This misclassification particularly affects Black people, who often have lower body fat percentages and higher muscle mass than white people with the same BMI. That means Black patients are more likely to be labeled as having obesity, even when their body fat is within a healthy range. Research also shows that BMI significantly underestimates obesity in Hispanic adults. A national study using DXA scans found that many Hispanic individuals with a “normal” BMI actually had obesity when their body fat percentage was measured. Of the 9,784 participants, 36% had obesity as determined by BMI, and 74% had obesity as determined by body fat percentage. They also tended to have higher abdominal fat, which is strongly linked to chronic diseases. This means Hispanic patients may be falsely reassured by a normal BMI, even when their true health risks are elevated. BMI can both overclassify and underclassify health risks; it should never be the only tool used to understand someone’s well‑being.
Luckily, there are several practical and affordable ways to get a clearer picture of your health.
1. Waist Circumference
Waist circumference measures how much fat is stored around the abdomen. MedicineNet explains that it is measured by wrapping a tape measure around the natural waist, just between the lowest rib and the top of the hip bone. It is simple and inexpensive, costing as little as $0.99 to $7. Research shows that waist circumference can predict disease development and health outcomes, which is crucial given what those numbers reveal. A waist circumference greater than 35 inches in women (34 inches in Asian women) and 40 inches in men (36 inches in Asian men) indicates higher abdominal fat, which is associated with several chronic diseases.
2. Waist‑to‑Hip Ratio (WHR)
WHR compares your waist size to your hip size to assess fat distribution and measure abdominal obesity. WHR is calculated by measuring waist circumference, then measuring the hip circumference at its widest point, and finally dividing the waist measurement by the hip measurement.
MedicineNet stated that a WHR above 0.80 in women and 0.95 in men indicates greater abdominal fat storage. This could increase the risk of heart and chronic diseases.
Additionally, a WHR lower than 0.80 in women and 0.95 in men suggests a higher fat storage in the hips. Higher hip fat indicates that the person is generally in good health, with a low risk of cardiovascular disease and mortality.
3. Skinfold Calipers
Skinfold calipers measure the thickness of fat just under the skin at specific body sites. According to Healthline, skinfold caliper measurements are taken at either 3 or 7 different sites on the body. The specific sites that are used vary between men and women. This measure is very affordable, portable, and quick to take. For personal use, the cost can be between $5 to $20. For professional use, it can be between $200 to $400. It is also important to note that accuracy depends on the skill of the person doing the test.
4. Body Circumference Measurements
Body circumference measurements estimate body fat by measuring areas such as the neck, waist, thighs, and hips. This method requires only a tape measure and a calculator, making it extremely low‑cost and easy to do at home. It is a quick way to get a general sense of body composition. Still, its accuracy varies because body circumference equations may not be accurate for everyone, given differences in body shape and fat distribution. Differences in body shape and fat distribution can lead to inconsistent results, so this method is best used as a rough guide rather than a precise measurement.
5. Bioelectrical Impedance Analysis (BIA)
BIA estimates body fat by sending a tiny, safe electrical current through the body. It is the technology used in many at-home body‑fat scales and handheld monitors. Since electrical currents flow more easily through muscle than through fat, the device can use this response to predict overall body composition. One drawback is accuracy, as readings can vary with hydration, recent meals, or the device’s quality. Yet, it still offers more information than BMI because it distinguishes between fat and muscle.
Why Understanding These Measures Is Essential
Deciding how to measure your body composition ultimately depends on what you value, whether that is accuracy, convenience, or simply having a tool you can use at home. These methods are affordable and accessible, making it easy to check your health regularly, even if they are not perfect.
It is important to recognize that BMI was never designed to capture the full picture of someone’s health. For many people, these alternative measurements offer a clearer and more equitable way to understand how the body stores fat and changes over time. For Black communities who have been misclassified and stigmatized by BMI for decades, exploring these options can help prevent future misdiagnoses and support more accurate and culturally aware care.
References
Is There a Better Alternative to Measuring BMI? | MedicineNet
The 10 Best Ways to Measure Your Body Fat Percentage | Healthline
BMI alone under-identifies obesity, particularly among Asian, Hispanic adults | Healio