Understanding Body Fat Pt. 1
If you ask most people what their training and nutrition programs are designed to achieve, the most common answer you will likely receive is “to reduce bodyfat”.
With reducing bodyfat often being the most common training goal, bodyfat is also one of the most misunderstood components of the human body. Before we understand what healthy ranges of bodyfat are, we must first understand what body fat is and what its role is in the human body.
Why does bodyfat exist?
The first idea to understand is that fat cells are essential in the body and play a key role in metabolism. Fat cells provide fuel for the body’s internal functions and physical activity. They help insulate the body and act as a protective cushion around vital organs. Recent studies have also shown that body fat acts as a hormone producing endocrine organ.
Body fat accumulation is the result of excess energy intake (high calorie intake) with limited energy expenditure (lack of exercise). Body fat acts as a metabolic storage tank where excess free fatty acids are stored as triglycerides. When the storage capacity is exceeded, fat begins to accumulate in areas outside the subcutaneous tissue.
Types of bodyfat:
Fat cells (adipose tissue) can be found beneath the skin (subcutaneous – SCAT) and around internal organs (visceral fat – VAT). These two types of fat have very different qualities and very different implications to general health. Below are some key characteristics of each:
VISCERAL ADIPOSE TISSUE – VAT
• Visceral fat accounts for up to 10–20% of total fat in men and 5–8% in women
• Located inside the abdominal cavity between organs
• Highly vascular and innervated
• Has a large number of inflammatory and immune cells
• Has a large number of glucocorticoid and androgen receptors
• Great capacity to generate free fatty acids
• Drains directly to the liver through the portal vein
SUBCUTANEOUS ADIPOSE TISSUE
• Fat cells lying directly under the skin
• About 80% of all body fat is in the subcutaneous area
• Main areas for subcutaneous fat deposition are the femerogluteal (bottom) regions, back and anterior abdominal wall
• Storage site for excess energy intake (high-caloric diet)
• Venous drainage is through systemic veins
• Can be measured using callipers
So looking at these two comparisons, we see that VAT is much more biologically active and is more of a highly functioning entity compared to SCAT. This has both its positives and negatives which we will look at shortly.
Different body types in relation to bodyfat:
The characteristics of your excess bodyfat distribution will have a large determinate on your body type. Those with excess bodyfat fall into two main categories – Gynoid (pear shaped) and Android (apple shaped). Those with apple body shapes (android) tend to have higher amounts of VAT compared to pear body shapes (gynoid).
Each of these body shapes comes with its own inherent issues and risks. Below are a common problems and risks associated with each:
Gynoid (Pear Shape)
• Often suffer from Gastro-Intestinal distress
• Often suffer from food allergies
• Swelling and increased water retention
• Often suffer from thyroid and adrenal imbalances
Android (Apple Shape)
• Greater risk of developing diabetes
• Insulin resistance
• Greater risk of developing cardiovascular disease
• Greater risk of developing metabolic syndrome
So we can see that the Android (apple) body shape, that has the higher prevalence of VAT, has the greater associated risk of chronic disease and diseases associated with high morbidity.
The heavy science about visceral abdominal fat:
So we are beginning to see that not all fat is created equal and that there are a large number of differences between the two types of fat. It is becoming clear that high amounts of VAT are not desirable.
We can see VAT is more biologically active than SCAT and therefore has a greater opportunity to influence the functions of the body, but when increased levels of VAT are directly correlated with morbidity, this is not a desirable influence. One of the reasons VAT has negative harmful effects on the body is its role as an endocrine gland. One of the compounds secreted by VAT is pro-inflammatory cytokines. These are proteins that, when secreted in large amounts are harmful to the body, as they result in negative effects such as increased levels of inflammation, tissue destruction and decreased insulin signalling. Proteins such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a) are the compounds that are directly responsible for causing the negative effects. The body requires certain amounts of these proteins to function optimally, but when there is higher than optimal levels of VAT, this can result in increased production of these potentially harmful pro-inflammatory cytokines.
As a KX gym supervisor, strength & conditioning personal trainer and functional medicine consultant, Aaron co-runs the KX Fitness Department and the unique KX Functional Assessments. Aaron is further responsible the continued education of the full team of KX Fitness Advisors and currently features monthly in Men’s Fitness as one of their “Resident Experts”.
• Gym Supervisor KX Functional Assessment Team
• Strength & Conditional Personal Trainer
• Functional Medicine Consultant
• ISSN certified Sports Nutritionist
• Runs KX Internship Educational Qualification