Good Fat vs. Bad Fat – A Better Indicator for Health than BMI
In your abdomen there are essentially two types of body fat: Subcutaneous [the fat that you can see and feel] and the Visceral Fat that wraps around your abdominal organs deep inside your body. You cannot feel or see visceral fat. In fact, you may have a flat tummy and still have excess visceral fat. Excess visceral fat is both genetic and lifestyle driven. In the old days this was called a ‘beer belly’ and is significantly associated with excess alcohol intake and excess carbohydrate intake but also influenced by genetic inheritance such that even modest dietary issues are contributors. The ‘gold standard’ for defining the amount of visceral fat is done using extremely low radiation dose conventional x-ray computed tomography. Specialized software uses the ‘density’ of fat on the CT scan [done roughly at the level of your belly button] to circumscribe the areas of both subcutaneous and visceral fat and the values are reported as cm2.
A recent investigation of 12,000 individuals at the Brigham and Women’s Hospital in Boston found that the visceral fat was independently associated with subsequent myocardial infarction [i.e. heart attack] and stroke; BMI or body mass index DID NOT!
For an elevated visceral fat, in the 4th quartile, the patients were statistically at highest risk for subsequent heart attack and/or stroke over the next two years compared to those with lower visceral fat measurements [see the figures below and presented recently at the Radiological Society of North America [RSNA] annual meeting in Chicago.
The Princeton Longevity Center pioneered this method of defining abdominal fat distribution and has measured visceral and subcutaneous fat in all patients and has done so for the past 20 years. We use this information, along with history/physical examination, blood sugar, cholesterol measurements, and CT heart/body scans to define your personal risk for cardiovascular disease.