Body Composition Part 1

The Vital Importance of Body Composition

Body composition is a critical component of metabolic health and there are multiple symbiotic mechanisms of body composition that support various other aspects of metabolic health.

In addition to supporting other components of metabolic health, maintaining balanced body composition is an essential aspect of healthy aging for various reasons. Poor body composition and particularly reduced muscle mass are a significant cause of morbidity and mortality in the elderly. This loss of muscle mass is known as sarcopenia and results in a progressive loss of strength and function. This increases the risk of falling and, in combination with reduced bone density (osteoporosis) elevates the risk of a hip fracture. In people over the age of 65, a hip fracture has been shown to lead to death in 27.3% of subjects after a year (1). 

Loss of muscle mass doesn’t just impact elderly. From age 30, we begin to lose an average of 3 – 8% of muscle per decade and this rate increases over the age of 60 (2). Having a plan to reduce the speed of this decline is an essential component of healthy aging so we can develop as much of a reserve of muscle as possible as we move towards and into the later decades of life.

General Targets and Goals

The Medicine with Heart approach seeks to reach not just normal, but optimal body composition for each individual based on both recognized levels of attainment and individual goals. Through this personalized approach, we are able to provide maximum wellness throughout the lifespan and to shorten the period of morbidity towards the end of life as much as possible. There are various aspects and life goals we aim to achieve through optimized body composition to maximize wellness and life fulfillment. 

These include:

• Increased muscle mass
• Improved metabolic function
• Cardiovascular health
• Balance and fall prevention
• High bone density 
• Capacity to perform the tasks of everyday living
• Maintenance of independence during the aging process
• Freedom to engage in activities that bring fulfillment during aging

Components of Body Composition

Although body composition can seem relatively simple (how much muscle, fat, and bone a person has) there are various ways to analyze and quantify body composition to provide a comprehensive picture and determine the most effective approaches to an individual plan for achieving optimal parameters. 

In part one of this blog series, the following components are reviewed:

• Weight
• Body mass index (BMI)
• Waist circumference
• Lean body mass
  • Muscle mass

Through targeting and optimizing each component of body composition, a broad range of benefits are realized. Below is a review of aspects of body composition and target ranges.

Body Weight

Weight simply refers to overall body weight without consideration of height and is the most basic parameter of body composition. It is a helpful initial picture of the amount of our mass though it does not take into account aspects such as height, lean mass, and fat mass. Monitoring this number is a simple at-home test that can be performed inexpensively and regularly with a scale to give a picture into the overall trajectory of whatever approach is being implemented to optimize body composition though more detailed and comprehensive testing is needed to ensure we are reaching goals. Specific weight goals are more accurately identified by the next parameter, body mass index.  

Body Mass Index (BMI)

Body mass index is based on a calculation of a person’s weight divided by height. This is generally a decent indicator of overall body mass as height is included in the equation. Although it is a more effective measure than body weight, it still doesn’t include how much weight is lean mass and how much is fat mass. For example, a bodybuilder with high levels of muscle mass may be classified as obese due to an elevated weight and be completely healthy as the majority of their body mass is muscle and not fat. 

Generally accepted BMI levels that correspond with health, underweight, and overweight include (National Institutes of Health): 

• Underweight = <18.5
• Normal weight = 18.5–24.9
• Overweight = 25–29.9
• Obesity = BMI of 30 or greater

To determine your BMI, follow this link.

At Medicine with Heart, we aim beyond normal for optimal and seek to establish a BMI that corresponds with the lowest level of all-cause mortality.

This range is:

• BMI of 20 – 22 (3)

As increasing longevity and healthspan are significant components of the Medicine with Heart journey, reducing all-cause mortality is an important indicator of target levels for optimization parameters. 

Another well-researched marker for body composition is waist circumference.

Waist Circumference

Waist circumference is a simple measurement of the abdomen around the navel area. To complete this, follow these steps:

• Stand
• Wrap a flexible tape measure around your abdomen in the navel area, just above the hips, and directly around the the back
• Breathe in and measure on the exhale

Although this is a cheap and simple test, elevated levels are a potential indicator for diseases and disorders such as (4):

• Metabolic syndrome
• Type 2 diabetes
• Hypertension
• High cholesterol
• Elevated uric acid 
• Obstructive sleep apnea
• Joint and back pain

Waist circumference is considered a better predictor of general health and a more accurate predictor than BMI (5). Adipose (fat) tissue around the waist is associated with greater risk of disease than adipose tissue on the buttocks and thighs, so measuring waist size provides more precise information than overall BMI. 

Desirable waist circumference for women and men are:

• Female < 35” (6)
• Male < 40” (7)

Beyond measuring weight, BMI, or waist circumference comes the wealth of information provided by a DEXA body composition scan.