Ectopic Fat
A nice overview I just thought I'd share here. Ectopic Fat Depots and Cardiovascular Disease
Waist circumference was one of the earliest means of quantifying body fat distribution, and some clinical guidelines have recommended measurement of waist circumference to provide additional information regarding cardiovascular risk.4 However, waist circumference consists of both subcutaneous adipose (SAT) (classically nonectopic) and visceral adipose tissue (VAT) (classically ectopic). This is important because VAT is associated with more adverse levels of metabolic risk factors compared with SAT.5 In addition, seminal work in mice has shown that transplantation of SAT, but not VAT, to an intra-abdominal site resulted in beneficial effects on metabolism.6 Taken together, these findings suggest that information about body fat distribution beyond waist circumference may provide important insights into metabolic and cardiovascular disease risk.
There's much more but one of the issues that is confusing is the role of abdominal fat in disease/risk. Not all apples are the same apparently. This reminded me of a post Stephan wrote a while back: Is it Time to Re-write the Textbooks on Insulin and Obesity? Part II. It contained this picture and caption.
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This is a photo from a paper titled "Insulin-sensitive Obesity" (2). According to the paper, that gentleman has a low insulin level similar to a lean person, and normal insulin sensitivity, despite having a body mass index of 45.2! This is true of a significant fraction of obese people, and it has been replicated in other studies (3). What differentiates insulin-sensitive from insulin-resistant obese people? Inflammation (2). Imagine that! |
Comments
I don't know whether the textbooks require an absolute re-write, but popular conception most certainly requires more depth and discretion that goes beyond this intellectually stunted nonsense about 'skinny fat' and 'pot bellies'; neither of them being relevant to the individual that I speak of in the paragraph above.
http://weightology.net/weightologyweekly/?page_id=260
I guess obesity is now a disease so it's too late I suppose, but the truth is that while most obese suffer some health complications, it is more those with a particular type of fat. I hate that my health is considered "at risk" merely because of BMI. If I had whacky lipids and such that would be a different story ...
http://www.reuters.com/article/2013/07/04/us-harder-workouts-idUSBRE9630GN20130704
After the sessions, the men ate 764 calories after resting, 710 calories after the moderate exercise, 621 calories after the high intensity workout and 594 calories after the very high
intensity workout.
Question 2: if you looked at VAT versus SAT using only a microscope, could you see the difference? What about with staining to see intracellular components? What about with immunostaining to see surface proteins?
most of the fat there is fat cells outside the muscle cells but within the muscle tissue.
> is fat ever accumulated outside of cells?
I think almost all of these are disease processes ... fatty arterial plaques would be the only significant fat outside of cells ... maybe in fatty liver?
I don't know if lipomas ever occur extra-cellularly.
Or more accurately, of the fraction of fat that's being oxidized, the fraction of trans fats being oxidized is very high relative to how much trans fats exist in the body. If one stays in calorie deficit The body's trans fats will disappear long, long, long before the other types.
the fraction of polyunsaturates being mobilized relative to how much is stored is lower than for trans and higher than for saturates, and so on
But sorry, I was unclear, I meant that the distinction of fat *stored* as VAT or SAT being good or bad (or neutral), was just throwing in the towel. Though some will say that it's impossible for them to lose weight.
Question: in all the hypocaloric metward studies, was any
subject ever released due to a medical urgency from their not being able
to handle the calorie restriction? In other words, many will say that undereatiing makes them sick, but is there a basis to that other than mere self-perception? Can practically all people just tough it out, or is that medically impractical?
That's an idea that would need to be tested.
I could imagine that "force-feeding" or "fire-hosing" a bunch of TFAs into your blood/liver/brain/whatever and through your mitochondria in a short time, which fasting may do, may not be as healthy as going into slight calorie deficit and letting the TFAs trickle out (assuming a small deficit will allow a trickle, not a dump)
I saw a lot of VAT in my days of animal research and it does look different to SAT that I also saw a lot of in cadavers. Could be species but I don't really think so. It's a texture thing.
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