Being fat has been linked to such dangerous health conditions as diabetes, cancer and cognitive decline. But fat tissue was long considered to be passive, hanging out lazily and doing damage without much effort. New research, though, shows that this isn't exactly true, especially in the case of visceral fat that can form around the organs of overweight and normal-weight people alike. Fat, reports Outside magazine, wants to keep us fat.
According to the magazine, numerous studies over the last two decades have revealed that fat tissue is essentially a "single huge endocrine gland" with great influence over the rest of the body. A certain amount of body fat is harmless and, in fact, necessary for survival. But excess fat is said to desensitize people to leptin, a hormone that plays a key role in satiety, and researchers at Yale University found that pools of fat in the muscles and liver can lead to insulin resistance and Type 2 diabetes -- conditions that, in turn, make it difficult to burn fat and control appetite.
"Fat is stubborn, demanding stuff," the magazine writes.
So what's the best way to wage war against fat? Exercise, according to some experts. Just as fat can "invade" muscle tissue, strong muscles can fight back. In 2003, biologists in Australia and Denmark figured out that muscle tissue secretes chemicals, known as myokines, that have a beneficial effect on organs -- one of them tells the liver to increase the rate of fat oxidation -- as well as bones, the immune system and other muscles, the magazine says. A 2012 Harvard study identified a hormone that is secreted during exercise and "tricks plain, blobby, 'white' fat" into becoming a type of fat that can burn energy as muscle does.
And you don't have to become super-lean to reap the benefits of regular exercise and strong muscles. "The most dangerous issue [for overweight people] is not being heavy per se but being sedentary," Bente Pedersen, the Danish physician and researcher who helped discover myokines, tells the magazine. "It's much better to be fit and fat," she says, "than skinny and lazy."