Are you scared that missing breakfast or even your mid-afternoon snack will send you into lean mass armageddon?!?! Relax. Theoretically, food deprivation would result in depleted hepatic glycogen stores, leading to increased proteolysis and flux of amino acids from skeletal muscle for hepatic de novo gluconeogenesis, to maintain healthy blood glucose concentrations. As discussed previously though, a 24 hour short term fast is insufficient in duration to deplete liver glycogen stores in healthy subjects (73). Up to 40 hours of total fasting does not stimulate catabolic processes and lead to skeletal muscle atrophy (82)... No loss of fat free mass in the absence of weight loss was observed compared to a control group fed a standardized diet (69). Furthermore, an increase in ketone body concentrations has been observed in subjects on alternate-day fasting diets in both human and animal studies (17,68). Ketone bodies spare skeletal muscle from breakdown by providing non-glucose energy substrate for various tissues, of which the brain is the most important, and thus decrease the need for protein-derived substrates for gluconeogenetic conversion to maintain glucose homeostasis (83). Available data thus suggests that short term fasting does not deplete hepatic glycogen stores to the extent that markedly increased proteolysis and gluconeogenesis becomes necessary to maintain healthy glucose concentrations lift-heavy/intermittent-fasting/ See Dr. John Berardi & Precision Nutrition for practical guidance.
Posted on: Mon, 09 Jun 2014 16:54:46 +0000