It’s common to have a goal weight in mind when drafting health and wellness goals. But body weight doesn’t tell the whole story when it comes to physical fitness. Body composition offers a more precise calculation by taking muscle, bone and fat into consideration – providing a more detailed assessment of musculoskeletal health.
What is Body Composition?
Did you know that muscle weighs more than fat? It does – which means it’s possible for a super-fit gym rat to weigh more than an overweight person of the same height. Understanding that body weight does not always correlate to ‘healthiness’ is key in appreciating body composition calculations.
Body composition considers the percentage of bone, muscle and fat that contribute to a person’s overall body weight. Because excess body fat is associated with higher rates of cancer, heart disease and diabetes, it’s important to understand whether those pounds showing up on the scale are coming from muscle or fat.
One way to assess body composition is to calculate body fat percentage, or the amount of fat that makes up a person’s body. Guidelines for body percentage increase with age. So 17-25% is considered an ideal range for a woman in her 30s, while a woman in her 60s should strive for a body fat percentage between 22-33%.
Is Body Composition the Same as BMI?
Not really. Lots of people get body fat percentage mixed up with BMI, which is calculated by dividing weight in kilograms by height in meters squared. Because BMI takes height into account, it’s a better assessment than body weight alone – but it’s still not as detailed of an assessment as body fat percentage or a complete body composition calculation.
5 Ways to Measure Body Composition
It can be tricky to assess body composition at home. These 5 methods are often used to assess body composition in a clinical setting:
- Skin calipers – measuring skinfold thickness in areas body fat is commonly stored, like the abdomen or arms.
- Air displacement – measuring body density using a pressurized chamber.
- Bioelectrical impedance – measuring conductivity by sending low-level electrical current through the body, as fat tissue is a poor conductor.
- DEXA scan – measuring body composition with a low-radiation bone density scan.
- Hydrostatic weight – assessing body weight underwater to calculate body density with this formula: density = mass/volume.
Weight Loss Isn’t the End Goal – Maintaining a Healthy Body Is.
While confronting obesity is often the first step in adopting a healthier lifestyle and reducing the risk of developing heart disease and diabetes, making the number on the scale drop at any cost isn’t always what’s best for a person’s health. After all, malnutrition and eating disorders can contribute to weight loss – at the expense of sacrificing the microbiome, muscle tone, mental health and more.
When you start considering body composition, it’s easy to see that weight alone isn’t enough to assess overall health. For a more precise understanding of fitness – and health risks associated with weight – additional calculations like body composition can paint a more complete picture.
