Know the enemy
By Christopher J. Stadtherr, MD
Not all body fat is created equal. Different types and different locations of fat have remarkably different effects on our health, yet there is very little discussion about it in typical health care settings.
Though we generally associate obesity with poor health, individuals with metabolic complications such as cardiovascular disease and diabetes are not necessarily more obese than individuals without these complications.
Obesity, then, by itself, is not a strong indicator of disease. The risk factor that is far more relevant than overall fat burden in predicting disease and mortality is the amount of visceral fat.
The Enemy that Lurks Beneath the Surface
Visceral fat is the fat that surrounds the internal organs of the body. In contrast to subcutaneous fat that is “pinchable,” visceral fat is deep within the torso. The majority of visceral fat is located in the central abdomen and is responsible for causing protrusion of the abdomen, the so-called “beer belly.”
Male-Female Differences
In general, men are more likely to store fat as visceral fat. Premenopausal women tend to store fat as subcutaneous fat, predominantly in the gluteal and femoral regions. As women transition into menopause, their decreasing estrogen levels drive an increase in the central distribution of fat and subsequent cardiometabolic risk.
The Repository for Excess Energy
Visceral fat appears to accumulate after the subcutaneous fat stores have reached capacity. How much fat can be stored in the subcutaneous fat depots is determined by one’s Personal Fat Threshold, which appears to be determined primarily by genetics.
Risks of Visceral Fat
Visceral fat is associated with cardiovascular risk and is a major predictor of coronary artery disease (CAD), with central abdominal fat being more predictive of heart attack than overall obesity.
It appears that an increase of 1 kilogram of visceral fat is associated with a 10-point increase in blood pressure. Visceral obesity is also associated with high triglycerides (hypertriglyceridemia) and small, dense LDL particles, which are more atherogenic (increased cardiovascular risk) than large, buoyant LDL particles.
As might be expected then, reduction of visceral fat is associated with significant improvement of cardiometabolic risk factors. There are several strategies to effectively reduce visceral fat and, subsequently, the risk of cardiovascular disease.
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