Many people use Body Mass Index or BMI to ascertain if their weight is still in the healthy range. Basically, BMI analyses if your weight is appropriate to your height. A BMI of 18.6 to 24.9 is deemed normal. If you get values lower than that range, you are underweight; higher than that and you might be overweight or obese.
While we often use BMI to assess if we are at risk of developing weight-related diseases, medical experts emphasize that it’s not the most accurate tool to measure someone’s fitness.
The more accurate tool is Body Fat Percentage which computes for your body’s fat mass.
BMI vs Body Fat Percentage
Why is a healthy body fat percentage better than a normal BMI?
According to experts, it’s because BMI is quite limited. While it can analyze the appropriateness of our weight to our height, it cannot distinguish between our body compositions.
You see, our body has two types of mass, namely:
- Body Fat. This is composed of both essential and excess fats. The essential fats are those that our body uses to protect our organs, regulate hormones, and store energy. The excess fats are those that we want to get rid of.
- Non-fat Mass. Aside from fats, our body is also composed of internal organs, water, muscles, and tissues, as well as bones. These are the non-fat composition of our weight and they are “metabolically active,” which means they burn calories.
So, let’s say you want to check your BMI. You’ll get your height and of course, measure your weight. When you use the bathroom weighing scale to check your weight, note that the number you see is your overall weight. It doesn’t distinguish between body fat and non-fat mass.
This makes BMI quite inaccurate.
Why? Because you can have a normal weight (BMI) but also have a high body fat percentage.
Simply put, body fat percentage measures how much of your weight is body fat. With BMI, doctors discovered that some people may be overweight, but not “overfat.” At the same time, they took note of people – some of them were even athletes – that have normal BMI but were overfat.
At this point, it is a must to highlight that a person who has a healthy weight, but overfat is just as unhealthy as someone who has above-normal BMI.
Healthy Body Fat Percentage Values
Healthy body fat percentage values differ between men and women. The American Council on Exercise provides the following ranges for Body Fat Percent Norms:
Essential Fats: 0–12%
Obese: 32% and higher
Essential Fats: 2–4%
Obese: 26% and higher
If you want to consider your age, here are the ranges:
20–39 years old: 21–32%
40–59 years old: 23–33%
60–79 years old: 24–35%
20–39 years old: 8–19%
40–59 years old: 11–21%
60–79 years old: 13–24%
As you can see, body fat tends to increase with age. Furthermore, women naturally have more body fat than men.
How Do You Measure Body Fat Percentage Then?
Since the weighing scale and BMI calculator are out of the question, how are you going to determine if you have a healthy body fat percentage? To have an idea of how much fat you have in your body, you can do the following:
Use a Bioelectrical Impedance or Smart Scales
A bioelectrical impedance or “bioimpedance” scale looks like a typical scale. But it comes with the added feature of providing body composition stats, including body fat percentage. It can do this by sending electrical impulses to the body and measuring how fast these impulses return.
Experts explain that electrical impulses travel faster in parts of the body that are made up mostly of water. In contrast, they don’t travel as quickly through fats and bones.
Although it’s quick and easy, the reliability of bioelectrical impedance scales depends on several factors. For instance, dehydration may lead to the overestimation of body fat. Also, people with pacemakers cannot use this device.
Use a Caliper to Measure Skinfold
Another way to check if you have a healthy body fat percentage is through the use of calipers.
Calipers measure the thickness of the subcutaneous fats in different parts of the body. Subcutaneous fats are the fats beneath the skin. The premise is this: the thicker the subcutaneous fats are, the higher your body fat percentage is.
Typically, you use the caliper in different locations, commonly the chest, abdomen, and thighs. Pull the muscle and then measure the fold using the caliper. Remember to measure twice and get the average. Once you get the measurements, you can input the numbers in an online calculator to determine your body fat.
The accuracy depends on how reliable your measurements are. Always pull and measure on the same side, preferably on the right side. Over time, you may not need online calculators. Like mentioned, the premise is if the fold is getting thinner, you are most probably losing fat.
Use a Measuring Tape
While you can get access to calipers and bioelectrical impedance scales, you may be surprised to know that you can also use the good old measuring tape.
What you need to do is measure the circumferences of different body parts, like wrist, hip, waist, and forearm. As with the case in using calipers, measure twice, and get the average. After getting the numbers, input them in a circumference body fat calculator along with other details like your height or weight.
Please note that this method is just an estimation of your body fat. The accuracy depends largely on your skill in measuring the circumferences.
Other Ways to Measure Body Fat Percentage
Aside from the three methods enumerated and explained above, you can also assess for your body fat using the following ways:
- Hydrostatic Weighing. One accurate way to check if you have a healthy body fat percentage is through hydrostatic weighing. In this method, you need to be fully submerged in a tank with water and the experts will measure how much water is displaced. It works on the idea that a person with more body fat weighs less underwater because fats are less dense compared to bones and muscles.
- Air Displacement (Bod Pod). This method is somewhat similar to hydrostatic weighing, but instead of water, the amount of displaced air will be measured. Air displacement is very accurate and it’s suitable for people of all ages and sizes.
- Dual Energy X-ray Absorptiometry (DEXA). To measure your body fat using this approach, you need to lie still while a machine passes over your body. The machine will emit x-ray beams and the technician will measure how the different body parts absorb the beam. From there, they will get the details of your body composition, including body fat and bone mineral density. DEXA is the “gold standard” for measuring the body composition as it not only determines body fat measurement but also its distribution.
The three methods explained above are more accurate than using smart scales, calipers, and measuring tapes. However, they are less accessible. Most tanks for hydrostatic weighing and Bod Pods for air displacement are not found in local gyms but educational or medical institutions. DEXA machine could be expensive depending on the brand.
While there are simple ways to determine if you have a healthy body fat percentage, the best way is still to consult a doctor. They will give you accurate measurements and advise you on the next steps. Basically, if your body fat percentage is too high, you will be recommended to work on decreasing it to have better health. Likewise, if it’s too low, you need to get the numbers up.
Learn more about Health Fitness here.
Hello Health Group does not provide medical advice, diagnosis or treatment.