The Carb-Sane Asylum

There was an article in the NYT that was passed along to me the other day: Exercise Hormone May Fight Obesity and Diabetes A newly discovered hormone produced in response to exercise may be turning people’s white fat brown, a groundbreaking new study suggests, and in the process lessening their susceptibility to obesity, diabetes and other health problems.

Boost metabolism? Well ... apparently not in rats. Fat feeding causes widespread in vivo insulin resistance, decreased energy expenditure, and obesity in rats full text in Google Docs HERE

I think I misunderstood the confusion many seemed to have over this recent post: Fat Futile Cycling ~ From Carb Excess? One of my readers posted a link to that post over at Mark Sisson's forum ... the responses were ... erm ... interesting.  Perhaps I'm not worthy of "writting" (<- commenter spelling, not mine) on this subject, but I can tell y'all that I'm definitely not some "poser" with an agenda to oppose low carb.  I'm not sure my diet these days qualifies as low carb in the VLC circles, but it certainly fits in with Sisson's 80/20% primal plan.  And I did lose most of my weight eating VLC most of the time.   In any case, apparently I presumed a bit more background on this topic than I should have.  So, here goes the laymen's terms explanation. In LC circles, there are many proponents of a so-called "Metabolic Advantage" of low carb dieting.  According to this theory, people lose more weight eating more L...

This post may well make heads spin.  It sure did mine. A common claim in LC circles is that we "waste" excess fats through futile cycling.  Although this has not been demonstrated in any significant amount in humans except in massive fat overfeeding, it is still incorporated into books and blog posts by the likes of Dr. Mike Eades (futile cycling to "blow off" low carb excesses is stated as if fact in The 6 Week Cure). Inherent in these statements is the implication that this only happens for excess dietary fat when carbs are low ... insulin would be trapping the fats in the cells as the theories go.  Well ... Substrate cycling between de novo lipogenesis and lipid oxidation: a thermogenic mechanism against skeletal muscle lipotoxicity and glucolipotoxicity   (2004 Review Article,  PDF)

Brown Fat and the Myth of Diet-Induced Thermogenesis INTRODUCTION:  The concept that brown adipose tissue (BAT) is a thermogenic tissue initially came from morphological changes in the tissue when animals were exposed to the cold (Smith and Horwitz, 1969). The physiological basis for the enormous capacity of BAT for heat production during cold exposure awaited the ingenious application of radiolabeled microspheres to measure blood flow in BAT and other tissues (Foster and Frydman, 1978). That production of heat occurred by uncoupling mitochondria was firmly established with the elegant experiments of Nicholls on physiology of BAT mitochondria and Ricquier’s identification of a unique cold-inducible protein in the mitochondria of BAT (Nicholls and Locke, 1984). The presence of large amounts of differentiated BAT in human neonates and species like sheep that require active thermogenesis at birth to protect the n...

Cell Metabolism Above is the general link to Cell Metabolism.  I tried to find a dedicated link to the FREE "issue" of Focus on Brown Adipocytes, but could not find it.  In any case, as of the date of this posting scroll down the home page for various articles on Brown Fat -- some of which I'll be blogging on here. Anyone who comes across this at some future date, I presume that one could go back to the June 2010 Issue.

A good summary:   http://www.sportsci.org/encyc/adipose/adipose.html

Everyone who believes Taubes' theories about Glycerol-3-P and not being able to store fat if you don't ingest dietary carbs should read this article. Glyceroneogenesis and the Triglyceride/Fatty Acid Cycle We make glucose via gluconeogenesis.  So, too, we make glycerol via glyceroneogenesis.  And we recycle ~50-65% of the FA's released via lipolysis back to trigs. One interesting thing is the behavior of brown adipose tissue.  The enzyme responsible for re-esterification, PEPCK-C is high in BAT.  But interestingly enough insulin INHIBITS this enzyme while a high protein zero carb diet stimulates it.   There's lots more  here to digest.  I'll revisit this post and update.