I had planned to read a magazine to pass the time at my CEU meeting on Monday. Instead, I found myself taking pages and pages of notes and actually learning a great deal about fat cells and disease. And it scares me to death to think what is happening to our collective health. Here is another subject where most folks are willfully ignorant–until it’s too late.
Being obese is not just about carrying too many pounds. We all know in a vague sort of way that as the pounds add up, so too do our risks of insulin resistance and diabetes, heart disease, sleep apnea and metabolic syndrome. And your risks correlate quite closely with your VAT.
VAT–Visceral Adipose Tissue: the fat deposited in–not over the top of–your abdomen. (In the greater omentum and mesentery of the intestines, if you must know the details.)
As your gut fat goes, so goes your health. Why? Because THIS particular fat population has a limited capacity to accomodate fatty acids in your blood. Past a certain critical point (which we don’t yet know how to measure or predict) your VAT sends fat out to the muscles, the heart, the pancreas and liver. This increases the likelihood of changes in insulin receptors body-wide, making insulin less and less effective at getting sugar into the cells. (Insulin resistance)
Currently held rule of thumb–or of girth, perhaps–from the American Heart Association: you have reached (and already been living with increasing levels of disease risk of VAT) if your waist reaches 40″ (guys) or 35″ (gals).
SCAT–subcutaneous adipose tissue–is what you wear under the skin, in your hips and thighs, for instance. It metabolizes fat differently, and can even make more fat cells to accommodate for a high fatty acid load in the blood.
You are at much less risk from a big butt than a big gut. Hence, the “apples and pears” body shape understanding of disease risk from obesity.
Understand too that fat tissue is not simply so much lard. These are living cells, and collectively we know now that adipose tissue is an endocrine organ: it secretes very many hormones not even known when I was learning my human biology in the Pleistocene: leptin and ghrelin (produced by the gut) are hormones that regulate hunger and satiety in the brain (and are involved in the relationship between obesity and sleep!); and adiponectin, a powerful metabolic protective hormone that comes from fat, but paradoxically diminishes as one becomes more obese.
The too-obvious everybody-knows take-home message: avoid adding those extra inches under your belt. It could save your life. If it’s too late for you, for gosh sake, don’t let it happen to your kids or grandkids.
For the truly nerdly, this is a great article from Nutrition and Metabolism on the differences between VAT and SCAT. Send it to a medically-oriented person you know.