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How Is Body Fat Percentage Calculated?

By Mosh
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Key Takeaways

Body fat percentage is a metric that measures the proportion of fat in a person's body compared to lean tissue, and it is crucial in assessing one's risk of developing diseases. While body mass index (BMI) is a commonly used method to determine weight and health status, other methods such as skin calipers, bone density scans and DEXA scans are more accurate in calculating body fat percentage.

Body fat percentage measures fat relative to body weight. When figuring out how to exercise for weight loss and how to lose fat, people have the question, ‘How is body fat percentage calculated?’ as they also wish to keep track of their progress.

Body fat percentage can be calculated in various ways. Most people use the body mass index (BMI), particularly a BMI calculator. Other methods include the skinfold method, bioelectrical impedance analysis, and hydrostatic weighing.[1]

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What is body fat percentage?

A bathroom scale may show how much you weigh, but that’s not the complete picture. In preventing obesity and other weight-related issues, it is important to watch how much fat one has compared to lean tissue. That’s where body fat percentage, or fat relative to body weight, functions as helpful information.

With our weight care programs at Mosh, we look at the big picture: everything that affects your weight, not just what you eat. Along the way, there are consultations with an AHPRA-registered doctor to make sure everything is tailored to your needs. When appropriate for your situation, your Mosh doctor may recommend meal replacement shakes, medical weight loss treatments, or diet coaching solutions.

BMI vs. body fat percentage

There are other methods besides stepping on a scale to assess someone’s level of fitness. BMI and body fat percentage are two metrics that are used to assess a person’s level of fitness and risk for diseases like diabetes and heart disease.

But when you ask ‘How is body fat percentage calculated?’ you may also wonder how these two metrics differ from one another. Let’s look at it more.

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Why is measuring my BMI important?

Measuring your BMI is a good way to figure out if your weight is ideal for your height. Knowing your BMI can help you and your doctor figure out if you have any health risks if your score is not in the healthy range. A BMI calculator is an easy-to-understand and extensively used method for measuring body fat percentage. 

To calculate your BMI, simply divide your weight in kilograms by the square of your height in metres. If you want to get even more specific views on the results, you can use this list to find your range:[2]

  • 18.4 and under = underweight
  • 18.5 to 24.9 = healthy
  • 25 to 29.9 = overweight
  • 30 and above = obese

Being overweight increases the risk of developing several different chronic illnesses including heart and blood vessel problems, type 2 diabetes, high blood pressure, musculoskeletal problems and cardiovascular disease.[3] Meanwhile, other health problems might arise as a consequence of being underweight, including the risk of malnutrition, osteoporosis, and anaemia.[4]

Although the BMI is not a perfect method for tracking essential fat loss,[5] it does give a general idea of whether you are gaining or losing fat.

Many people who are trying to lose weight use their BMI as a way of tracking their progress.[6] When you begin to lose weight, you may want to keep an eye on your BMI to make sure you aren’t losing too much too quickly. Once you get closer to your goal, you can use your BMI as a way of tracking if you’re maintaining your optimal body weight.

Mosh understands how important it is to take care of your weight, and that’s why we’re committed to making health advice more accessible and more normal. You can fill out our short online questionnaire, and our doctors will get back to you within twenty-four hours with personalised and science-backed recommendations. You can even ask ‘What is a healthy body fat percentage?’ or ‘How to lose body fat?

How do I find out my optimal body fat percentage?

A healthy body fat percentage – defined as the part of your total body weight that is made up of body fat in relation to lean mass, organs, tissues, and water – is important to have when assessing your risk of disease.[7]

Body fat percentage can be determined in a variety of ways, from using skin calipers to more sophisticated equipment like dual-energy X-ray absorptiometry or DEXA scans.[7] Knowing your body fat percentage makes it easier for you to identify if you need to focus on growing lean body mass or reducing fat mass, both of which reflect healthy body composition changes.[8]

It may be challenging to identify a single ‘optimal’ percentage because what may be excellent for one person may not be so for another.[9]

To help people understand how is body fat percentage calculated and where they stand in terms of their health, ranges are usually used. Figures can differ based on your source, and these may further depend on your age, sex, or other factors. For the American Council on Exercise (ACE), 18 to 24 per cent is regarded as acceptable for men, while 25 to 31 per cent is regarded as acceptable for women.[10]

To ask about the body fat percentage for your unique conditions or even questions like ‘Is body fat percentage accurate?’ you can talk to a Mosh doctor. Our platform is dedicated to helping you get the results that you want – the sooner, the better.

What is the most accurate method of calculating body fat percentage?

lthough there are several ways to determine body fat percentage, some are more precise than others. Your body fat percentage tells you much more about your health than just your weight, so it pays to check which ones are the most accurate. Common methods include:[10]

  • A bone density scan, where a special type of x-ray called dual-energy x-ray absorptiometry (DEXA) is passed through your body.
  • Hydrostatic weighing, where the amount of water that is displaced when you are underwater is used to calculate your body fat percentage.
  • Skinfold measures, sometimes referred to as ‘pinch tests’, can be taken with callipers.
  • Whole-body densitometry is used in air displacement plethysmography or Bod Pods to determine a person's body composition.
  • Body composition can be precisely determined using magnetic resonance imaging (MRI) and computed tomography (CT) images.

The most precise methods of determining body fat, such as hydrostatic weighing, Bod Pods, and CT/MRI scans, are more expensive and scarcer than alternative techniques. Calipers and other simple scales, on the other hand, run the danger of being inaccurate.[11] Depending on where you reside, DEXA may be the most reliable and accessible method of measuring body fat out of those discussed above.[11]

Body fat percentage can help you determine your fitness and nutrition improvement. To track your progress, consider recording your weight, body fat percentage, and measurements. You can even keep a journal to document everyday progress.

Talk to your Mosh doctor about a program that suits your weight care needs. Your doctor will review your concerns, condition, and even history to provide you with personalised advice. If appropriate, your doctor may recommend weight loss programs to help you lose weight. These may include weight loss shakes, which can be delivered to your doorstep and refilled as you need it.

If you are recommended our plans and opt to subscribe, you’ll even get access to weekly meal plan guides, a comprehensive dashboard, and a supportive community. You’ll also get unlimited free doctor’s consultations, so you’ll be able to update your doctor on your progress and make adjustments as needed.

If you have concerns regarding how to lose body fat, how to walk to lose weight, or how to reduce belly fat, you’ll be able to ask your doctor over text, call, or video chat. 

Talk to a Mosh doctor whenever you’re ready.

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