Body Composition: Definition and Insights Into Health
Body composition refers to the distribution of fat, muscle, bone, and other tissues that make up your body. It is often expressed as the percentage of total body weight that consists of fat and/or lean body mass. Body composition offers numerous insights into health, fitness, and nutritional status.
Body fat plays a key role in hormone production, insulation, and other important body processes. While the optimal amount of body fat differs from person to person, having too much body fat increases the risk of various health issues, from joint problems to heart disease.
Fortunately, there are several strategies to improve body composition and your overall health. This article discusses what body composition is, why it's important, and how to improve yours.
What Is Body Composition?
Body composition is the term used in the fitness and health community to refer to the percentage of fat, water, bone, muscle, skin, and other lean tissues that make up the body.
While checking your weight on the scale can be helpful for seeing your total weight, it doesn’t tell you how the weight is distributed in your body.
Body composition is typically broken up into two groups:
- Fat mass refers to the body's stored fat. Fat insulates the body, surrounds your organs, and is used for energy.
- Non-fat mass refers to all of your body's components except fat. Non-fat mass includes bones, liver, kidneys, intestines, muscles, and other organs and tissues your body needs to function.
Many health risks are tied to the ratio of fat mass to non-fat mass. Research shows that the risk of premature death is greater in people who have higher percentages of fat compared to non-fat mass.
In comparison, people with higher percentages of non-fat mass compared to fat mass tend to be leaner with more muscle. These individuals have a lower risk of many diseases.
Body composition is a valuable tool for assessing:
- Health status: Body composition assesses the percentage of fat in the body. Having excessive body fat, especially fat around organs (visceral body fat), increases the risk of many health conditions, including heart disease, diabetes, and several cancers.
- Fitness levels: Athletes and fitness enthusiasts can use body composition as a tool to track their lean muscle-building progress. Body composition helps athletes optimize their strength, endurance, and overall athletic performance.4
- Nutritional status: Body composition can help you and your healthcare provider understand if you have too much or too little body fat relative to your weight. This information can be used to design a safe and effective diet intervention or meal plan.
- Metabolic health: Having excess fat increases the risk of metabolic health issues, including insulin resistance, imbalances of cholesterol and triglycerides, high blood pressure, uncontrolled blood sugar, and slowed metabolism. Body composition is therefore an effective tool for monitoring and reducing these risks.
- Weight control: Weight loss is often accompanied by a loss in lean body mass, especially muscle, which can impede long-term weight loss by slowing metabolism and increasing fatigue. Monitoring body composition helps maintain lean body mass while also shedding body fat.