Visceral Fat (VAT): Definition and Causes

What is Visceral Fat?

Visceral adipose tissue (VAT) is a type of fat that is located in the abdominal cavity and wraps around organs such as the intestines, pancreas, and liver. It is called visceral fat because this fat is close to viscera, i.e., internal organs. In order to understand what VAT is, it’s important to address adipose tissue and its types.

The term adipose tissue refers to body fat, i.e., connective tissue that extends throughout the human body. Your adipose tissue can be classified into two types:

●      White adipose tissue: also known as white fat, is the most abundant type of adipose tissue in the body. It is present throughout your body, including the abdominal cavity and under your skin. White adipocytes (fat cells) have a simple structure comprising several cellular organelles and a single lipid droplet (fat molecule).

●      Brown adipose tissue: also known as brown fat, is usually present in infancy and reduces with age. Brown adipocytes are more complex than their white counterparts; they contain multiple lipid droplets and cellular organelles. The main function of brown adipose tissue is to transfer energy from food into heat to keep you warm when you’re cold.

When it comes to location, your adipose tissue is classified into:

●      Visceral adipose tissue: a type of white fat that surrounds organs in your abdominal cavity.

●      Subcutaneous adipose tissue: a type of white fat situated between the skin and muscles.

Adipose tissue is also present in other areas of the body, including bone marrow, breast tissue, and around your heart.

Visceral fat vs. subcutaneous fat

Visceral fat and subcutaneous fat are the main representatives of white adipose tissue. The main difference between them is that subcutaneous fat is located between your skin and the outer abdominal wall. On the flip sid, visceral fat is found in spaces between abdominal organs and the omentum (the apron-like adipose tissue structure found in front of abdominal organs).

Abdominal fat contains both subcutaneous and visceral adipose tissue. In fact, 90% of body fat accounts for subcutaneous adipose tissue, whereas the remaining 10% is visceral fat.

Visceral adipose tissue is more metabolically active than subcutaneous fat. For that reason, its impact on your metabolic health is far more significant. Fat cells in visceral fat are different than those in subcutaneous fat, actually. According to a paper from Obesity Reviews, compared to subcutaneous fat, visceral fat is more cellular, vascular, and innervated, and features more inflammatory and immune cells. Visceral fat also has a greater percentage of larger adipocytes.

Due to these differences, excess visceral body fat is considered more dangerous to your overall health and well-being.

Why do we store excess fat in the abdominal area?

The abdominal area is quite stubborn. Most people struggle to lose weight in this specific area and find it difficult to tone their stomachs. Excess fat in the abdominal region results from the following:

●      Genetics: some people have a genetic predisposition to store fat in certain areas, including the abdomen. A paper from Endocrinology and Metabolism reported that genetics sets a foundational baseline for the storage, distribution, and metabolism of fat. Genetics could be the reason why Asians tend to accumulate higher visceral fat over subcutaneous fat compared to Caucasians, Hispanics, and Africans.

●      Lifestyle: A sedentary lifestyle, unhealthy diet, and lack of sleep can contribute to excessive fat in the abdominal area. Evidence confirms that lack of physical activity significantly increases visceral fat. In one study, people who didn’t exercise exhibited an 8.6% increase in visceral fat after eight months,while those who exercised experienced an 8.1% reduction in visceral fat during the same period. At the same time, eating more calories than you burn through physical activity also adds to visceral fat. The exact mechanism of action through which an unhealthy diet increases visceral fat is yet to be elucidated, but changes in gut microbiota could play a role. A study from the International Journal of Obesity linked higher visceral fat mass to E. dolichum, a strain predominant in obesity and metabolic dysfunctions.

●      Hormones: sex hormones (estrogen and testosterone), stress hormone cortisol, and insulin can influence the way your body stores fat. Hormonal imbalances could make you more susceptible to developing excess fat in the abdominal region. For example, low concentrations of estrogen can lead to the accumulation of VAT in women. At the same time, lower testosterone levels are associated with an increase in intra-abdominal fat and predispose men to higher visceral adiposity. Producing too much cortisol can also lead to the accumulation of body fat in the abdominal area because this hormone can affect blood sugar levels and affect how your body retains weight. After all, hormones are chemical messengers that coordinate various functions in the body.



In the next articles, we wil discuss why VAT is important, how you can measure it, what a “normal” level is, and how to reduce it.

Did you know? Excessive amount of visceral adipose tissue predisposes you to a wide range of health problems. It hinders athletic performance in active men and women too. The only way to know whether you have excessive VAT is to schedule your DEXA scan. You can do so with Fitnescity. Through access to your personal dashboard, you can track progress and modify your lifestyle to reach your goal and reduce VAT successfully.