Are You Skinny Fat?

Obesity continues to be strongly associated with multiple chronic conditions, such as hypertension, diabetes, lipid abnormalities, and heart disease. It also strongly contributes to development of certain types of cancer. The rates of obesity are alarmingly high in young children and adolescents, and, unfortunately, continue to rise. According to the AHA/ACC and The Obesity Society Guidelines released in 2013, obesity continues to be defined as measurement of the body mass index, or BMI.  Using BMI, overweight is defined as BMI of 25 kg/m2 to 29.9 kg/m2 and obesity as a BMI of 30 kg/m2 . Current estimates are that 69% of adults are either overweight or obese, with approximately 35% obese. The estimated cost of obesity related complications exceeded $147 billion in 2008.

However, estimating obesity by BMI tells only part of the story. A muscular individual may have a BMI exceeding 30kg/m2, due to a much higher water (and weight) content associated with skeletal muscle. More relevant to the cardiac risk associated with obesity are the measurements of waist circumference. It is generally accepted that the waist circumference should not exceed 35 inches in women, and 41 inches in men. These numbers are 1-2 inches smaller for individuals of European, Asian, or Hispanic descent.

A fascinating and powerful concept in understanding obesity goes beyond  these numbers and involves a  body impedance analysis, or BIA. Using the BIA, a percent of fat deposited in the abdominal cavity (visceral fat) can be distinguished from a more superficial fat distribution. Only visceral fat is associated with elevated risk for heart disease. A 2004 study in The New England Journal of Medicine convincingly demonstrated that removing superficial fat, such as with liposuction, does not alter risks for diabetes or  heart disease. Unlike superficial fat, visceral fat may be present unseen in a skinny person, and increases their risk of insulin resistance and heart disease. The accumulation of visceral fat drives inflammation, contributes to oxidative stress, and disrupts hormonal and immune regulation.

The  diminish visceral fat, an anti-inflammatory diet, supplements, in combination with workouts (moderate intensity but consistent) work to reverse the inflammation, and normalize internal fat metabolism, and, thus, its distribution.  Unfortunately, in our appearance-based society, many fail to see that “skinny” does not always imply “healthy”. Quiet a few skinny people are in fact “skinny fat”, with deposits of visceral fat driving their sugar and lipids into abnormal range. Visceral fat also traps a lot of toxins, including so called persistent organic pollutants (POPs), and this exacerbates ongoing inflammation by disruption of nutrient absorption.

What should you do? If you have access to the BIA machine, often found in gyms or physician offices, consider getting a reading done. A functional medicine physician can perform the BIA, and review the report in conjunction with your blood work. This assessment, while relatively simple, is a crucial step in understanding your metabolic circumstances, and putting your personal genetic information in perspective.