Anyone trying to lose weight knows it's all about burning off the unhealthy excess fat. But it turns out that not all fat is created equal—and not all people who need to lose fat even know about it. To get the low-down on which type of fat you need to lose—and what you need to eat to get there—we spoke to Manuel Villacorta, MS, RD, CSSD, one of the leading nutritionists in the San Francisco Bay Area, and founder of the interactive weight-management web site Nutrition for You. Villacorta makes a clear distinction between two kinds of fat: subcutaneous fat, which is stored between skin and muscle; and visceral fat, which accumulates around organs, especially the liver. Visceral fat, which cannot even be accessed by liposuction, is significantly more dangerous than subcutaneous fat.
What makes visceral fat so dangerous? The visceral fat cells literally function differently than subcutaneous fat cells. "In comparison to visceral cells, subcutaneous cells are greater in number," Villacorta says. "But the visceral cells are actually larger in size per cell. And they get to be so big that they atrophy themselves—at which point they constantly, 24/7, produce cytokines." Cytokines are a hormone with known inflammatory properties. "They promote atherosclerosis, tumor growth, aging, oxidation, hypertension, and cardiovascular disease." That's quite a laundry list of bad things!
Because visceral fat is stored around the liver, it impacts liver function as well. "The liver processes fats," Villacorta explains, "and because these fats surround it, the liver has to keep processing them—and with them processing a lot of LDL, or bad cholesterol." That means more artherosclerosis—and hardened arteries. "If you have this fat you can consider yourself always in a low-level inflammatory state," Villacorta says. "It is a chronic condition—always happening, again and again."