What Is Body Composition? Importance, and How to Measure

Body composition refers to the percentage of fat, bone, muscle, organs, and water that make up a person’s total body mass. It provides an indication of overall health and fitness beyond simply measuring body weight. Assessing body composition allows tracking changes in fat mass versus lean tissue over time. This can help monitor weight loss progress and athletic performance. There are various methods available to measure body composition, each with their own advantages and limitations.

Understanding your unique body composition can provide insight on health status, disease risk, metabolic function, training status, and more. While concepts like body mass index (BMI) offer general guidelines for weight status, body composition assessment looks more specifically at tissue composition rather than relying solely on height and weight. Used properly, body composition testing empowers individuals to make informed lifestyle choices regarding diet, exercise, and other behaviors that influence body makeup.

What Is the Meaning of Body Composition?

Body composition refers to the percentage of fat mass and lean body mass that makes up a person’s total body weight. Lean body mass includes muscle, bone, organs, water, and everything else in the body besides fat. Body fat percentage specifically quantifies the proportion of fat mass relative to total body weight. For example, a man weighing 180 pounds with 15% body fat would have 27 pounds of fat and 153 pounds of lean mass.

What Is the Meaning of Body Composition
What Is the Meaning of Body Composition?

Assessing body composition provides a more detailed perspective on health and fitness compared to looking only at body weight or BMI. Losing 5 pounds could mean losing valuable muscle mass rather than fat, which would be detrimental. Gaining 5 pounds of muscle mass can improve health, while gaining 5 pounds of fat worsens it. Evaluating changes in fat mass versus lean tissue offers unique insights not provided by weight or BMI alone.

What is the Importance of Body Composition?

There are several reasons why body composition is important to evaluate beyond simply measuring body weight. These include knowing your health status, assessing weight loss progress, monitoring training adaptations, guiding nutrition needs, and tracking trends over time.

  • Indicates health status: Higher fat levels increase risk for conditions like heart disease, diabetes, and cancer. Lean tissue influences strength, recovery, and metabolic health.
  • Assesses weight loss progress: Scale weight can stay the same while fat decreases and muscle increases, indicating positive change.
  • Monitors training adaptations: Muscle gain in athletes signals positive response to training, even if weight stays stable.
  • Guides nutrition needs: Metabolic rates differ for fat tissue versus lean tissue.
  • Tracks trends over time: Gradual body composition changes may affect health before weight changes.

In summary, body composition provides insights into health, fitness, training status, metabolism, and progress that weight or BMI alone cannot offer.

What 3 Things Make up Body Composition

There are three essenetial components that make up ones body composition; fat, bone, and muscle. Each of these three play an important role in the body and should be thoroughly understood.

What 3 Things Make up Body Composition
What 3 Things Make up Body Composition

1. Fat

Body fat makes up essential fat, which protects organs and provides insulation and energy reserves, as well as storage fat, which accumulates in excess. Essential fat is around 2-5% in men and 10-13% in women. Healthy storage fat ranges are 6-17% for men and 14-27% in women typically. High body fat levels, especially around the abdomen, raise risks for chronic diseases.

2. Bone

Bone provides the structural framework that supports the body and allows movement. Bone also houses bone marrow, which produces blood cells. The amount of bone mass peaks around age 30 then gradually declines with age. Maintaining bone strength through exercise, nutrition, and lifestyle helps prevent osteoporosis.

3. Muscle

Skeletal muscle accounts for roughly 40% of total body weight on average. It produces movement via contraction and increases metabolism. Muscle mass can fluctuate with training, diet, and age. Higher lean muscle mass boosts strength, mobility, and metabolic rate.

What Does Body Composition Measure?

Body composition testing aims to quantify the percentage of fat mass and lean body mass to determine a person’s overall tissue makeup. This provides an estimate of total body fat percentage as well as proportions of muscle, bone, and fluid balance. Testing modalities utilize a variety of mechanisms to differentiate between fat and lean components.

What Are Ways to Measure Body Composition?

There are five main ways to measure body composition; Hydostatic Weighing, Skinfold Measurement, BodPod, Dual Energy X-ray Absorptiometry, and Bioelectrical Impedance Analysis.

What Are Ways to Measure Body Composition
What Are Ways to Measure Body Composition?

1. Hydrostatic Weighing

Hydrostatic weighing determines body composition based on buoyancy during water submersion. Lean tissue is denser than fat, so less buoyant bodies have higher lean mass. While accurate, access to specialized equipment is required.

2. Skinfold Measurement

Skinfold calipers measure fat levels by pinching skin folds at select sites on the body. The thickness of folds provides an estimate of subcutaneous fat in those areas. Considerable practice is needed for reliable results.

3. BodPod

The BodPod assesses body composition using air displacement plethysmography. Body volume is measured while sitting in the enclosed chamber and used to estimate fat and lean mass proportions based on known tissue densities.

4. Dual Energy X-ray Absorptiometry (DXA)

DXA scans use two x-ray beams to differentiate bone, fat, and lean tissue based on differential energy absorption. DXA provides whole body composition breakdown plus segmental analysis of regions.

5. Bioelectrical Impedance Analysis (BIA)

A Bioelectrical Impedance Analysis (BIA) device sends a small electric signal through the body with electrodes. Fat impedes signal conduction since it contains less water than muscle. BIA is fast and accessible but sensitive to hydration status.

What Is a Normal Body Composition?

Normal body fat ranges are quite broad, generally 10-22% for men and 20-32% for women on average. Athletes can be as low as 6-13% men and 14-20% women. Higher levels, especially abdominal fat, increase health risks. Aim for lower normal ranges unless your goals require extreme leanness.

What Are the Benefits of Normal Body Composition?

Maintaining a normal body composition within healthy ranges provides many benefits such as lowered risk of disease, better physical performance, enahnced metabolic function, increased strength, improved mobility and balance, and a sense of confidence and accomplishment.

  • Lower disease risk
  • Better physical performance
  • Enhanced metabolic function
  • Increased strength
  • Improved mobility and balance
  • Sense of confidence/accomplishment

What Are the Disadvantages of Having an Abnormal Body Composition?

Abnormal body composition can negatively impact health. High body fat raises risks for heart disease and stroke, Type 2 diabetes, high blood pressure, and certain cancers.

  • Heart disease and stroke
  • Type 2 diabetes
  • High blood pressure
  • Certain cancers

Very low body fat or muscle can impair immunity, fertility, strength, performance, and recovery.

What is a Good Body Composition?

A good body composition includes lower body fat in the healthy range for your age and gender, well-developed muscle mass, strong bones, and adequate hydration. The optimal composition promotes health, physical performance, mobility, metabolism, and sense of well-being.

How Much of Your Body Composition Should Be Muscle?

There are no standardized percentages for how much muscle your body composition should be comprised of. A general guideline is around 30-50% of total mass for men and 20-40% for women on average. Athletes often exceed 50% muscle mass. The optimal amount depends on goals, sex, genetics, and age.

How to Improve Body Composition?

Ways to improve body composition include engaging in strength training, following a calorie-controlled and nutrient-dense diet, increasing activity, adressing stress or sleep, and being both patient and consistent.

  • Engage in strength training to build muscle
  • Follow a calorie-controlled, nutrient-dense diet
  • Increase activity through cardio, sports, or lifestyle
  • Address stress, sleep, and other lifestyle factors
  • Be patient and consistent with long-term changes

Can You Improve Body Composition by Dieting?

Yes, an appropriate calorie-controlled diet can improve body composition. Reducing calories alone risks muscle loss. However, pairing diet with strength training while meeting protein needs helps maximize fat loss versus lean mass loss.

Can You Improve Body Composition by Exercising?

Yes, proper exercise directly improves body composition. For example, aerobic exercise burns calories to reduce fat mass. Strength training also stimulates muscle growth. Consistency is key for long-term body composition benefits.

What Exercises Improve Body Composition?

Effective exercises include strength training with weights, resistance bands, or bodyweight; HIIT workouts; steady state cardio like running or cycling; and full body metabolic conditioning circuits.

Is Body Composition Your Overall Weight?

No, body composition does not refer directly to overall weight or body mass. Rather it describes the composition of weight in terms of fat mass versus lean mass. Changes in weight can result from gains or losses in muscle, fat, water, or other tissues.

Is Body Composition the Same as BMI?

No, body mass index (BMI) and body composition are not the same. Your BMI only uses total weight and height. Body composition analyzes the composition of weight into fat mass and lean body mass. Also, BMI does not distinguish between fat, muscle, or bone mass.

What Is the Difference Between Body Fat Percentage and BMI?

The main difference between body fat percentage and BMI is that body fat percentage directly quantifies fat mass while BMI only uses total weight and height. BMI cannot distinguish between fat, muscle, bone, and other tissues. Changes in body fat percentage better indicate true changes in body composition than BMI.

Is Body Composition Also Referred to As Body Fat Percentage?

Yes, body fat percentage is one specific metric used to assess overall body composition. Total body fat percentage quantifies fat mass relative to total body weight. body composition more broadly also estimates levels of lean tissues like muscle, bone, and water in the body.

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Athletic Insight Research


The Athletic Insight Research team consists of a dedicated team of researchers, Doctors, Registered Dieticians, nationally certified nutritionists and personal trainers. Our team members hold prestigious accolades within their discipline(s) of expertise, as well as nationally recognized certifications. These include; National Academy of Sports Medicine Certified Personal Trainer (NASM-CPT), American College of Sports Medicine (ACSM), National Strength and Conditioning Association (NSCA-CPT), National Academy of Sports Medicine Certified Nutrition Coach (NASM-CNC), International Sports Sciences Association Nutritionist Certification.