Body Composition

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton, Uchechukwu Chukwuemeka and Kim Jackson

Introduction

The body is composed of water, protein, minerals, and fat. A two-component model of body composition divides the body into a fat component and a fat-free component.

• A body composition analysis gives you a quick snapshot of your health by breaking apart your body into these two types of mass: body fat and fat-free mass.
• Having a full understanding of body composition, by getting it properly measured, will give you personalized insights that take the guesswork out of a person's health status .

Body Fat

Body fat is the most variable constituent of the body. The total amount of body fat consists of essential fat and storage fat.

1. Essential fat is necessary for normal bodily functioning. Fat in the bone marrow, in the heart, lungs, liver, spleen, kidneys, intestines, muscles, and lipid-rich tissues throughout the central nervous system is called essential fat
2. Body storage fat refers to all the fat in your body, such as the fat around your organs or abdomen (visceral) and the “jiggly” fat seen under the skin (subcutaneous). Visceral fat (abdominal), is non-essential and having it in excess can increase susceptibility to chronic illness and health complications.

One of the conditions associated with central obesity is Metabolic Syndrome

Fat-free Mass

Fat-free mass covers all the things in the body that aren't fat, including muscles, bones, water (both intracellular and extracellular), minerals, proteins, organs, and other tissues.

• Lean body mass represents the weight of muscles, bones, ligaments, tendons, and internal organs.
• Lean body mass differs from the fat-free mass. Since there is some essential fat in the marrow of the bones and internal organs, the lean body mass includes a small percentage of essential fat. However, with the two-component model of body composition, these sources of essential fat are estimated and subtracted from total body weight to obtain the fat-free mass.

Misconceptions

Standard bathroom scale will provide an easy metric for monitoring weight over time, however, that number doesn’t accurately tell the health story. It’s like looking at the cover of the book and thinking you know the complexities of the plot lines inside.

Efforts to lower or raise weight are often based on popular misconceptions about body weight and body composition. Being thin does not necessarily reduce one's health risk. Obsession with becoming thin often leads to serious eating disorders such as anorexia and bulimia.

• Thinness simply refers to weighing less than the recommended values in age-height-weight tables.
• Leanness, on the other hand, refers to the muscle, bone, and fat composition of the body weight. Although some lean individuals may weigh more than their "tabled" ideal body weight, low body fat lessens the risk of health problems.

Body mass index (BMI), another frequently used measurement of health, generates a value based on height and weight that broadly categorizes individuals as being underweight, normal, overweight or obese. The equation however is imperfect and can be misleading. It’s entirely possible to have a body mass index (BMI) in the “healthy range” but still be at risk for disease and chronic illness because of the way the mass in your body is distributed.

Body Composition Analysis

By breaking the body down to its core components through a full body composition analysis, you can accurately measure and track changes in muscle mass, fat mass, and body fat percentage over time which can help in identifying the areas you need to work on to lower your risk of disease and improve your overall health. The following are 4 body fat measurement techniques that are often accessible to fitness professionals: hydrostatic weighing, radiography techniques (DEXA scan, CT scan, MRI scan), bioelectrical impedance, and skinfolds.

Image: Calipers used for skinfold tests.

• Hydrostatic weighing, also known as underwater weighing or hydrodensitometry, is one of the most accurate ways to measure body fat. This is done by submerging yourself in a tank of water and being weighed underwater. The measurements can then be broken down to determine your fat and fat-free mass, including your lean tissue and muscle mass. May be available at a local wellness clinic or a doctor may be able to recommend a facility that offers hydrostatic testing. Some gyms with a pool will offer this service to clients. It was considered the gold standard for measuring body composition until more advanced methods, such as CT scans and MRI scans, were developed.
• Bioelectrical Impedance Analysis (BIA): This technique uses body fat and lean muscle mass as the basis for measurement by way of either a handheld device or a BIA scale. Small electric currents are sent through the body and because water, fat, and lean tissue mass interact with the currents differently the devices can accurately assess the distribution of your mass.
• Skinfold Measurements: Done by pinching the skin with callipers in seven different areas on the body, can provide a quick and relatively accurate estimate of body fat that can be compared to others of similar age and gender. This technique, while quick and requiring very little equipment, does not paint a complete picture of the different types of fat or how and where your body is storing it.
• Radiography techniques such as DEXA, CT, and MRI scans are also the gold standard for estimating body composition. This procedure uses radiological or electromagnetic waves to estimate the weights of body components such as bone, water content, fat deposits, and muscle mass. The cons are that is not readily accessible for routine checks, it is expensive and can only be used by licensed radiography professionals.

The video below further elaborates on the different body composition techniques

Physiotherapy

Knowing a client's body composition is more informative than focusing on their body weight since it gives the measure of both fat mass and fat-free mass.

• For instance, if a person begins an exercise program, they may gain 1 kg of muscle in the first month. At the same time, they may lose 1 kg of fat due to burning more calories through exercise or changes in diet. Since the fat-free mass increased by the same amount as the fat mass decreased, the body weight won’t change.
• If a person focuses on their weight, they may become discouraged or frustrated because the program “isn’t working.” This is one example of why knowing body composition is much more useful than knowing body weight.

Physical activity and exercise are components for improving body composition.

• They not only increase the calories used, but they are also necessary for optimal muscle growth.
• Body composition can be improved by decreasing fat mass or increasing muscle mass.

Many types of exercise can potentially help with fat loss: Interventions that combine high‐intensity aerobic and high‐load resistance training exert beneficial effects that are superior to any other exercise modality at decreasing abdominal adiposity, improving lean body mass and increasing cardiorespiratory fitness. Clinicians should consider this evidence when prescribing exercise for adults living with obesity, to ensure optimal effectiveness.