Not all fat is created equal. This fact is well-known to nutritionists and scientists, who have for some time understood that visceral fat—that is, the fat in the abdomen that surrounds the vital organs—is particularly bad for people's health. Now a new study seems to indicate that the dangerous effects of this particular kind of fat can be mitigated by even a moderate amount of exercise. And that is very good news for anyone who is feeling a little thick around the middle.
How exactly visceral fat cells differ from subcutaneous (under-the-skin) fat cells is not entirely clear, but it is clear that visceral fat produces inflammatory effects in the body. In particular, excess visceral fat has been consistently associated with insulin resistance and diabetes as well as heart disease. Because the fat cells in the belly put inflammatory molecules into the blood stream, and because chronic inflammation is increasingly associated with a wide variety of ailments, scientists speculate that visceral fat may soon be firmly associated with cancer and with many of the effects of aging. So there's a lot at stake in getting belly fat under control.
But for anyone who despairs of conquering his waistline, here's the good news: you may be able to make a big change in the effects of visceral fat even without making a big change in your overall shape. So suggest researchers at the University of Illinois who conducted a study on mice to determine the effects of diet and exercise on visceral fat and its inflammatory effects. The results are published in the May issue of the American Journal of Physiology: Endocrinology and Metabolism. In the study, the researchers divided mice (who had been fed a high-fat diet to generate big tummies) into several categories: sedentary, low-fat diet, exercise, and diet with exercise. The diet with exercise group was further divided into mice studied for six weeks and ones studied for 12, to see the differences in duration. The mice were monitored for their amount of visceral fat and its degree of inflammation, measured in part through insulin resistance and liver function. Their results were startling, even to the researchers themselves.
First, the only mice who gained visceral fat in the study were the sedentary mice. All the other mice—so long as they did something, diet or exercise or both—either lost fat or stayed the same. Even so, combining diet with exercise didn't yield a substantially better result than just diet or exercise alone. This was a big surprise to researchers, who expected to see that the mice had to actually lose the visceral fat in order to reap benefits. In fact, mice who continued to eat a high-fat diet but were on the exercise program managed to keep inflammation at bay. And here's the kicker: these exercising mice were hardly sweating themselves to death. In fact, as study researcher J.A. Woods explains, "This was a very modest exercise program. The mice ran on a treadmill only about one-fourth of a mile five days a week. For humans, that would probably translate into walking 30 to 45 minutes a day five days a week." This potentially means that quite moderate exercise can have strongly beneficial effects on visceral fat, even in the presence of a high-fat diet and persistent weight issues.
As Woods puts it, "Even if you struggle with dieting, we believe you can still reduce the likelihood of developing obesity-related inflammatory diseases, such as Type 2 diabetes and heart disease, by adding a modest amount of exercise to your life." Bottom line: it's worth getting out there and moving around, even if you're not going to achieve the perfect body. You don't need to be (or look like) a marathoner for exercise to seriously help your health. And every little bit you do counts.