Until fairly recently, fat was thought to be inert, evolution’s wobbly way of letting humans store energy for lean times. Starting in the 1990s, though, scientists began to realize that fat is best understood as a single huge endocrine gland, one that wields powerful influence over the rest of the body. “For a typical North American, their fat tissue is their biggest organ,” says James Kirkland M.D., director of the Robert and Arlene Kogod Center on Aging at the Mayo Clinic.
Not everything about fat is bad. Fat tissue under the skin, known as subcutaneous fat, is essentially padding that protects the body from injury, and it also helps fight infection and heal wounds. The bad news is that, as we age, we gradually lose this good fat, which is one reason why our hands get bonier. Instead we tend to develop blobby fat around our midsections. Researchers have recently discovered that this so-called visceral fat infiltrates our vital organs, bathing them in a nasty chemical stew that wreaks havoc in the body, leading to chronic inflammation and the release of chemicals that have been linked to cancer. Dr. Kirkland and other researchers have come to believe that, in addition to diabetes and heart disease, fat may actually accelerate the aging process. As if this the above is not bad enough, in sedentary people fat infiltrates both the liver and muscle cells and increases the likelihood of developing diabetes. On a strictly mechanical level, more fat means less muscle and less muscle means decreased ability to burn calories.
As you can see from the above, once you start to gain fat and lose muscle the odds increase that you will continue to put on fat, both because of compromised metabolism and an alteration in your hormones created by the imbalance between muscle and fat. The solution is to exercise more and eat only enough to support the energy needs of the level of exercise you are doing. In addition, cutting calories and eating fewer carbohydrates will take you a long way toward solving the problem.