John Robert Cardillo

What is Body Fat?


Body fat is commonly known as “adipose tissue.” Fat cells are a major storage site for fat in the form of triglycerides. It is the part of our body mass that is not bone, muscle, organ or water (fat cells do contain water, but in small amounts relative to muscles and organs). Fat found between our skin and our muscle wall is called subcutaneous adipose tissue. This substance is considered an important heat insulator for the body. The degree of insulation depends upon the thickness of this fat layer; the more subcutaneous fat a person has, the more comfortable he or she will feel in colder temperatures.

Body fat is comprised of adipose cells that are circular in shape, and are made up of 90% triglycerides, with small amounts of free fatty acids, cholesterol, diglycerides, monoglycerides and phospholipids. Fat cells also contain a nucleus and a mitocondrion, which because of the stored fat content, are compressed to one side of the cell wall. Adipose (fat) cells are basically “areolar” connective tissue modified to hold or store nutrients. Areolar connective tissue is the most abundant type of tissue in the body. It contains a semi-fluid, or gelatin-like substance. The term “areolar” means “a small, open space,” a type of tissue that provides a reservoir of water and salts for surrounding body tissues, and which holds as much fluid as there is in the entire bloodstream. This tissue acts as a packing material between other tissues, and binds body parts together while allowing them to move freely over one another; wraps small blood vessels and nerves, forms skin tissue, and surrounds glands. Adipose tissue is also located around the organs, in bones, within the abdomen and in breasts.

John Cardillo’s take on what body fat is.

The Fat Cell

The structure of adipose cells is a bit different from other cells, in that the adipose cell’s nucleus (the “brain” of a cell) is pushed off to the side by a large fat droplet. Their function is to provide a reserve of food fuel, to insulate against heat loss (fat is a poor conductor of heat and helps prevent heat loss), and to support and protect organs. Fat also holds and provides the “essential fatty acids” necessary for normal growth.


Fat cells are among the largest in the body, and are incapable of cell division (unlike the cells of the liver, muscles, skin, etc.). As they take up fat, they become larger and plumper, and as they release the fat, the skin takes on a more wrinkled look. When speaking of cellulite, what is happening to create that “dimpled” look under the skin is similar to enlarging soap bubbles, in that they push and shove each other until some lift to the surface; and so, rather than having a smooth, uniform look to the skin, the skin’s surface looks bumpy. In effect, cellulite is not a type of fat, but a descriptive term of how the fat cells are organized because of their excessive size and dimpled, layered look. Even in normal-weight individuals, fat cells are closely packed together and give a chicken-wire appearance to the tissue.

Adipose tissue is very vascular, and the network of blood through the area indicates that there is a lot of metabolic activity taking place through the fat cells. This is necessary to either store or release energy for survival, confirmed by the fact that we could not live for more than a few days without food if fat stores did not exist. In the average man, 15 kg of stored fat is capable of providing about eight weeks of energy, whereas the body will hold only about 12 hours of energy in the form of glycogen in the liver and muscles.

Heredity and Body Fat

When we are born, the genetics we inherit determine the number of fat cells we will have, and their location. Our parents have everything to do with our physical hereditary characteristics, and there is a great likelihood that we will be predisposed to store body fat where they did, thus resembling their physical characteristics.

Each person has a different number of body fat cells located in greater or lesser numbers in various anatomical places. Our anatomy is such, that if our muscles were covered with skin without any body fat in between, we would be ideal in size for our bone structure and frame. Leaving the issue of thermogenesis (the production of heat in the body) aside, the lack of fat between our skin and our muscles would be a great thing for all of us. Our true shape would be self-evident, and the only other determining factor as to how we could look aesthetically would be the size and shape of our muscles. It is the size of the fat cells in between the skin and our muscles that determines our actual body shape.

Heredity – Not a Detriment

Because it is impossible to eradicate our bodies of fat cells, the only alternative is to shrink all of our fat cells to their smallest possible size. That can be accomplished only through proper nutrition and intense exercise.

The fat deposits throughout our body, such as around the abdomen and hips, are predetermined genetically, from your mother and father. You may have large hips, or be prone to different fat around the “love handles,” for instance, whereas other individuals will have different body shapes, because of skeletal structure, muscles shapes and fat deposits. Regardless of what was handed down to you, hereditary factors should not be used as an excuse for being overweight, or to carry more body fat than what is “normal” under healthy living conditions. Regardless of the number of fat cells found in the body and how large those fat cells become, often as the result of lack of activity and eating the wrong foods, a hi-intensity workout program will work for you. Actual obesity, as a result of genetics, counts for only 3% of the overweight population, whereas the remaining overweight individuals simply live an unhealthy lifestyle.

Is it Thick Skin or Body Fat – the Pinch Test?

Skin thickness refers to the space between the skin and muscle wall, or in other words, fat. The actual skin epidermis is about 1/8 of an inch thick at its maximum. Sometimes people believe they have “thick skin,” when in fact they really have too much fat under the skin that gives the appearance of thickness.

Each fat cell has limitless capacity to enlarge (inflate) as a person overeats and more triglycerides are stored in the fat cell. Excessive storage of triglycerides is called obesity. Because fat cells have a large capacity to expand, they can easily become the storehouses of calories from excessive eating.

We exercise in order to reduce the size of our fat cells as much as possible so that our true shape, or muscle structure, can show. People tend to look their best when they have very little fat between the skin and muscles. The goal of my HIT3 weight training program and Shredded Nutrition program is that our skin is tighter against our lean muscles. For more information on HIT3 and SNP, visit




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John Robert Cardillo

bodybuilding champion

A Canadian champion who went on to win many bodybuilding competitions including the Junior Ontario and Junior Canadian Championships.

John Robert Cardillo

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