How Do Fat Cells Work in the Human Body

It is always better to know the working system of your body as it helps you maintain good health. One factor that tells you about your health is your weight. Whether a person is healthy, overweight or obese is determined through his/her BMI (Body Mass Index). A healthy person has a BMI between 18.5 to 25. A person who is overweight has a BMI between 25 to 29 whereas a BMI of 30 determines the person as obese. We know that when we put on weight we look fat, however, keep wondering about where does that extra fat come from and how fat cells work in the human body.

What are Fat Cells?

Fat cells, also called adipocytes or lipocytes, are the empty tanks that store the body fat (adipose tissue) in the form of triglycerides. It is present around the heart, kidneys, visceral organs below the epidermis (skin) and also in the sole of the feet and in the hips. This stored fat is called subcutaneous fat. It is used in the form of energy (carbohydrates) whenever required. Whenever the fat is stored, fat cells expand and when it is extracted by the body, they shrink. Fat cells also do the job of getting rid of the excessive fat.

Formation and Working of Fat Cells

Formation
Many people have a misconception that fat cells can be formed at any stage of life. But, it is not so. They are formed inside the growing fetus during the third trimester of pregnancy. The fat in newborn babies is stored in the form of brown fat used in thermogenesis i.e., generating heat, while in adults only white fat is active. The number of fat cells remain constant throughout life only the amount of fat stored in it varies. But, there are two exceptions to this constancy of number. Firstly, if a person gains a significant amount of weight and secondly if he/she undergoes liposuction. Once the fat cells are formed during pregnancy, their distribution between men and women takes place at the onset of puberty. The storage of fat in an adult body depends on a person's gender. In an adult man fat is stored in his chest, abdomen and buttocks whereas in a woman, it is stored in her breasts, hips, waist and buttocks.

Working
The fat or adipose tissue does not remain only a fat storage tank but acts as an active tissue and communicates with other tissues, including pancreas, liver and muscle tissue. It acts as a shock absorber and an insulating material. It metabolizes lipids and fatty acids that are absorbed from the food and converts it into energy. Whenever the body needs energy to perform any activity, it breaks down the fat into free fatty acids. These acids are then passed to the liver and converted into usable energy. This is how the fat cells get rid of the excessive fat. It can also convert sugars to fat and fat to sugars through metabolism. Fat cells also make major contribution in controlling the immune system of the body. When these cells are small, they form a protein hormone called adiponectin which regulates blood sugar level and prevents heart diseases. These cells however, when enlarge, do not form adiponectin which is why people who are overweight or obese, develop heart diseases and diabetes easily. Fat cells also smoothen the body by filling up all the sharp angles between the muscles and the bones.

Working of Fat Cells in Obese People

Fat tissue malfunctions in obese people. Obese people tend to consume too many calories regularly which makes fat cells overgrow to store them. There is cellular stress on the tissue for increased metabolism. This can lead to low oxygen supply to the tissue causing the death of individual cells. The fat tissue most importantly fails to communicate with other tissues which doesn't happen in a healthy person. This leads to the common diseases like type 2 diabetes and cardiovascular diseases.

Since fat tissue works in connection with other tissues in the body, and performs an important task of energy production, proper functioning of fat cells inside the fat tissue becomes very important.