Abdominal Fat

What is VAT?
VAT (Visceral Adipose Tissue) is fat that is deposited around the organs in the abdominal cavity. VAT is different than subcutaneous fat (fat just under the skin) in that you cannot pinch it. VAT is far more dangerous than subcutaneous fat and more metabolically active. Accumulation of VAT is associated with insulin resistance and results in a complex of symptoms (high blood pressure, high cholesterol, high triglycerides and high fasting glucose) known as the metabolic disorder (or Syndrome X). VAT occurs in both sexes, but is more prevalent in men and postmenopausal women.

How can we measure VAT?
The waist to hip ratio (WHR) is a common way to determine the severity of VAT accumulation. Higher ratios indicate more VAT accumulation. Ratios above 0.8 for a woman and 0.95 for a man indicate an unhealthy level of VAT.

What causes VAT?
Insulin resistance appears to be the strongest primary cause of excess VAT. In fact, a high WHR is strongly associated with fasting insulin, total whole-body glucose disposal and glucose oxidation. Also, other factors associated with insulin resistance are also positively correlated with a high WHR, including triglycerides, hepatic lipase (HL) and HL/LPL ratio. Likewise, factors negatively correlated with insulin resistance are also negatively correlated with WHR including HDL.

Many hormone systems are also involved. Androgen levels appear to be involved, but the research is conflicting. For instance, some studies have found that DHEA-S levels are associated with abdominal obesity, while other have found a reverse correlation. A decline in growth hormone levels appears to be a contributer, along with increases in cortisol.

What can be done to reduce VAT?
The same things that improve insulin sensitivity will also reduce VAT. Weight loss is the number one thing here. Minimizing dietary intake of saturated fats, trans fats and omega-6 polyunsaturated fatty acids is also hugely important. Monounsaturated fats (like olive oil) and omega-3 polyunsaturated fatty acids (like fish and flax oil) improve insulin sensitivity. Fiber intake is negatively correlated with WHR. Pectin appears to be the most effective fiber for reducing WHR. Increasing protein while reducing carbohydrate intake also improves WHR.

Exercise is extremely effective for improving insulin resistance and eliminating VAT. Walking works well for this. But higher intensity exercise works better.

Some supplements that show promise for reducing VAT include pantethine, taurine, calcium and tea. Stimulants should be avoided due to their direct effect on cortisol levels and indirect effect on insulin sensitivity.