Types of Body Fat
Each type of body fat is not the same. They differ based on their function and location in your body, and are labeled by "colors" (but not actually colors).
According to the Harvard School of Public Health, our fat cells can grow in size and number. The amount of fat cells in our bodies is determined soon after birth and during adolescence and tends to be stable throughout adulthood if weight remains somewhat stable. Eating too many calories in the long term can cause fat cells to increase in size and get stored in various areas throughout the body, which leads to a risk of chronic inflammation and glitches in a healthy metabolism, with the potential for new fat cells to grow.
These larger fat cells become resistant to insulin, which increases the risk of type 2 diabetes and cardiovascular disease. Weight loss can reduce the size of fat cells but not the number.
Colors of Fat
Most fat cells in your body are white fat. They soak up dietary fat and store it for future energy needs. White fat cells can continue to grow larger. If you eat too much dietary fat, they will keep getting bigger – potentially to the point of dysfunction.
Brown fat cells interact with white fat cells to burn energy in cold weather and create heat. Lean people have more brown fat than non-lean people. Brown fat is now thought to be more like muscle than like white fat. When activated, brown fat burns energy from white fat.
Beige fat cells are also mixed in with white fat. We have more beige fat than brown fat. Beige fat cells are inactive until you get cold. Then they start burning energy like brown fat cells, just not as well. The research is learning more every year about the role of beige fat.
Essential fat may consist of brown, white, or beige fat and is vital for the body to function normally. It is found in most organs, muscles, and the central nervous system including the brain. It helps to regulate hormones like estrogen, insulin, cortisol, and leptin; control body temperature; and assist in the absorption of vitamins and minerals. When a person’s body fat dips below a certain level (about less than 5% in men and less than 10% in women), there may not be enough essential fat to perform these functions.
This type of white fat is sometimes referred to as “belly fat” or “central obesity,” as it accumulates deep in the abdominal cavity, wrapping around digestive organs like the pancreas, intestines, and liver but also the heart. Having excess visceral fat is linked with a higher risk of cardiovascular disease, diabetes, and certain cancers.
You can pinch this layer of fat that sits directly underneath the skin’s surface, cushioning the bones and joints. It’s the body’s most abundant type of fat and tends to accumulate around the waist, hips, upper back, buttocks, and thighs. Very high amounts of subcutaneous fat can increase the risk of disease, though not as significantly as visceral fat.
Intramuscular fat is generally considered to be any fat (including the fat between muscle groups and within a muscle) found beneath the fascia of a muscle and is the widest definition for fat beneath the fascia of a muscle. Intramuscular fat is the visible fat found within a muscle.