How does your body "burn" fat?

Many of us are thinking of "burning a little fat" so that we feel better in our swimsuits on the beach or at the pool. What does it really mean, though?

The normal fat cell exists mainly for storing energy. The body will increase the number of fat cells and the size of fat cells to meet the excess energy of high calorie foods. It even goes as far as to start depositing fat cells on our muscles, liver and other organs to create a space to store all that extra energy of high calorie diets – especially when it is combined with a low-activity lifestyle.

Historically, fat storage has worked well for humans. The energy was stored in the form of small packets of molecules called fatty acids, which are released into the bloodstream to be used as fuel by the muscles and other organs when there was no food available, or when a predator was chasing us. Fat storage actually provided a survival advantage in these situations. Those who tend to store fat are able to survive longer without food and have extra energy for hostile environments.

But when was the last time you fled a predator? In modern times, with an overabundance of food and safe living conditions, many people have accumulated excess fat storage. In fact, more than a third of the adult population in the United States is obese.

The major problem with this excess fat is that fat cells, called fat cells, do not function normally. They store energy at an abnormally high rate and release energy at an unusually slow rate. What's more, these extra fat and enlarged fat cells produce abnormal amounts of different hormones. These hormones increase inflammation, slow down the metabolism and contribute to the disease. This complicated pathological process of excess fat and dysfunction is called adiposopathy and makes the treatment of obesity very difficult.

When a person starts and maintains a new exercise regime and limits calories, the body does two things to "burn fat". First, it uses the energy stored in fat cells to fuel a new activity. Second, it stops storing a lot for storage.

The brain signals fat cells to release energy packets, or fatty acid molecules, into the bloodstream. The muscles, lungs and heart capture these fatty acids, separate them and use the energy stored in the links to perform their activities. The remaining remains are thrown away as part of breathing, in the outgoing carbon dioxide, or in the urine. This leaves the big cell empty and makes it useless. The cells actually have a short life span so when they die, the body absorbs the empty cast iron and does not replace them. With time, the body directly extracts the energy (ie calories) from the food to the organs that need it instead of storing it first.

As a result, the body readjusts by decreasing the number and size of fat cells, which subsequently improves basal metabolism, decreases inflammation, treats disease and prolongs life. If we maintain this situation over time, the body reabsorbs the extra empty fat cells and rejects them as waste, leaving us thinner and healthier on many levels.

David Prologo, Associate Professor, Department of Radiology and Imaging Sciences, Emory University

This article was originally published on The Conversation. Read the original article.

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