The Carb-Sane Asylum

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)

High-fat diet, muscular lipotoxicity and insulin resistance A high dietary fat intake and low physical activity characterize the current Western lifestyle.  Dietary fatty acids do not stimulate their own oxidation and a surplus of fat is stored in white adipose tissue, liver, heart and muscle. In these organs intracellular lipids serve as a rapidly available energy source during, for example, physical activity. However, under conditions of elevated plasma fatty acid levels and high dietary fat intake, conditions implicated in the development of modern diseases such as obesity and type 2 diabetes mellitus, fat accumulation in liver and muscle (intramyocellular lipids; IMCL) is associated with the development of insulin resistance. Recent data suggest that IMCL are specifically harmful when combined with reduced mitochondrial function, both conditions that characterize type 2 diabetes. In the (pre)diabetic state reduced expression of the tra...