1. GETTING TO GRIPS WITH VISCERAL FAT
Not all body fat is ‘bad’, as we need it to insulate and cushion our organs. It is when we have it in excess that it starts to affect our health, especially if we start accumulating it in our abdomen around our organs. This type of fat is called visceral fat, and the aim of this chapter is for you to get a deeper understanding on why excess visceral fat can make you sick. Don’t worry if you find this section a bit technical – you can always revisit it as your understanding grows.
TYPES OF FAT
ADIPOSE TISSUE
The primary function of body fat – or adipose tissue – is to store and release energy, and to serve as insulation and cushioning for organs. Adipose tissue consists of fat cells, known as adipocytes, along with other supporting cells and blood vessels. Adipocytes produce adipokines, which are hormones and cytokines. The precise definitions of whether something is classified as a hormone or a cytokine is subtle and not important in the context of this book; just know that they are both types of chemical messengers.
There are two main types of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is the predominant type and is responsible for storing excess energy as triglycerides (more about thesehere). WAT is found throughout the body, primarily under the skin (subcutaneous fat) and around the organs (visceral fat).
On the other hand, BAT is more abundant in infants and is involved in generating heat to maintain body temperature. Brown adipocytes contain a higher number of mitochondria (the little powerhouses that are in our cells, generating energy), which give them their characteristic brown colour. When activated, brown adipose tissue can ‘burn’ the stored fat and release heat, contributing to energy expenditure and thermoregulation (body temperature).
It is important to know that adipose (fat) tissue is not only used for energy storage and cushioning for our organs, but can also act in a way similar to an endocrine organ because of the hormones and cytokines it produces. In basic terms, these are messengers that, upon arrival to the target cells, tell the cell what to do. The body is constantly monitoring hormone levels, as we should not have too much or too little of any of them, but rather maintain a balance (called homeostasis). When something goes wrong in the body, this homeostasis is under threat, and adipose tissue plays its part in either keeping things in check – or causing havoc.
SUBCUTANEOUS FAT AND VISCERAL FAT
It is important to distinguish between subcutaneous fat and visceral fat.
Subcutaneous fat helps to regulate our body temperature. It also provides us with protection, as it cushions our organs, bones and muscles. In addition, it serves as energy storage. We have subcutaneous fat all around our bodies. It is located directly under the skin, and you can typically pinch it.
Visceral fat is also needed to protect our organs, such as the liver and pancreas. It helps with insulating them from the cold, and it can also act as an energy reserve; therefore, we do need some of it. It is when there is